All questions
Question 1
Convert 2.4 gallons to cups. Use 1 gallon=4 quarts, 1 quart=2 pints, and 1 pint=2 cups.
- 19.2 cups
- 9.6 cups
- 38.4 cups (correct answer)
- 4.8 cups
Explanation: We need to convert 2.4 gallons to cups using a chain of conversions. Set up the conversion factors: 1 gallon = 4 quarts, 1 quart = 2 pints, and 1 pint = 2 cups. Using dimensional analysis: 2.4 gallons × (4 quarts/1 gallon) × (2 pints/1 quart) × (2 cups/1 pint) = 2.4 × 4 × 2 × 2 = 38.4 cups. Notice how the units cancel: gallons cancel with gallons, quarts with quarts, and pints with pints, leaving only cups. A common mistake is multiplying by only one or two conversion factors instead of using the complete chain. For multi-step conversions, write out all units to ensure proper cancellation.
Question 2
A container holds 6 pints of juice. Using 2 pints=1 quart and 4 quarts=1 gallon, how many gallons of juice is this?
- 0.375 gal
- 0.75 gal (correct answer)
- 1.5 gal
- 3 gal
Explanation: We need to convert 6 pints to gallons using a two-step conversion. First, convert pints to quarts: 6 pints × (1 quart/2 pints) = 6 ÷ 2 quarts = 3 quarts. Then convert quarts to gallons: 3 quarts × (1 gallon/4 quarts) = 3 ÷ 4 gallons = 0.75 gallons. The units cancel appropriately at each step. A common error is trying to convert directly from pints to gallons without the intermediate step, potentially using an incorrect conversion factor. For multi-step conversions, work through each unit systematically.
Question 3
A runner completes 10 kilometers. Convert this distance to meters.
How many meters are in 10 kilometers?
- 100 m
- 10000 m (correct answer)
- 1000 m
- 100000 m
Explanation: We need to convert 10 kilometers to meters using the metric system conversion factor. Set up the conversion: 10 kilometers × (1000 m/1 km). Calculate: 10 × 1000 = 10,000 meters, with the kilometer units canceling out to leave meters. The key metric conversion is that 1 kilometer = 1000 meters, since 'kilo' means 1000. A common error is using 100 instead of 1000, confusing kilometers with hectometers. In metric conversions, always check the prefix: kilo = 1000, hecto = 100, deka = 10, and the base unit has no prefix.
Question 4
A swimming pool holds 2500 gallons of water. Convert this volume to liters. (1 gallon = 3.785 liters)
Convert 2500 gallons to liters.
- 3785 liters
- 9462.5 liters (correct answer)
- 10000 liters
- 946.25 liters
Explanation: We need to convert 2500 gallons to liters using the given conversion factor of 1 gallon = 3.785 liters. Set up the conversion with the provided factor: 1 gallon = 3.785 liters. Using dimensional analysis: 2500 gallons × (3.785 liters/1 gallon) = 9462.5 liters. The gallons units cancel out, leaving us with liters as our final unit. Students might round 3.785 to 4 and get 10,000 liters, or confuse the conversion direction. Always use the exact conversion factor given and set up the fraction to cancel unwanted units.
Question 5
A field is 3000 square meters. Convert this area to square kilometers. (1 km = 1000 m)
Convert 3000 square meters to square kilometers.
- 0.003 square kilometers (correct answer)
- 0.03 square kilometers
- 0.3 square kilometers
- 3 square kilometers
Explanation: We need to convert 3000 square meters to square kilometers using the linear conversion 1 km = 1000 m. Set up the area conversion by squaring the linear conversion factor: (1 km)² = (1000 m)², so 1 km² = 1,000,000 m². Using dimensional analysis: 3000 m² × (1 km²/1,000,000 m²) = 0.003 km². The square meter units cancel out, leaving square kilometers. A critical error is using the linear conversion factor (1000) instead of the squared factor (1,000,000) for area conversions. Always square the linear conversion factor when working with area units.
Question 6
The length of a room is 5 meters. Convert this length to centimeters.
How many centimeters are in 5 meters?
- 5000 cm
- 500 cm (correct answer)
- 50 cm
- 5 cm
Explanation: We need to convert 5 meters to centimeters using the metric system conversion factor. Set up the conversion: 5 meters × (100 cm/1 meter). Calculate: 5 × 100 = 500 centimeters, with the meter units canceling out to leave centimeters. The key conversion factor to remember is that 1 meter = 100 centimeters in the metric system. A common mistake is confusing this with millimeters (1000 mm = 1 m) or forgetting the factor of 100. When working with metric conversions, remember that each step up or down the scale involves factors of 10, 100, or 1000.
Question 7
A metal rod has a mass of 1.8 kilograms. It is cut into 6 equal pieces. Using 1000 g=1 kg, what is the mass of each piece in grams?
- 0.3 g
- 30 g
- 300 g (correct answer)
- 3,000 g
Explanation: We need to find the mass of each piece when a 1.8 kg rod is cut into 6 equal pieces, with the answer in grams. First, convert the total mass to grams: 1.8 kg × (1000 g/1 kg) = 1800 g. Then divide by 6 to find the mass of each piece: 1800 g ÷ 6 = 300 g per piece. Alternatively, we could divide first (1.8 kg ÷ 6 = 0.3 kg) then convert (0.3 kg × 1000 g/kg = 300 g). Either order gives the same result. When problems involve both unit conversion and other operations, you can often choose the order that seems easiest.
Question 8
A moving company transports 3.6 tons of furniture. Using 2000 lb=1 ton, how many pounds is 3.6 tons? Do not divide by 2000; you are converting to a smaller unit.
- 1,800 lb
- 5,600 lb
- 7,200 lb (correct answer)
- 72,000 lb
Explanation: We need to convert 3.6 tons to pounds. Since 2000 lb = 1 ton, we multiply by 2000: 3.6 tons × (2000 lb/1 ton) = 3.6 × 2000 lb = 7200 lb. The ton units cancel, leaving pounds. A common error is dividing by 2000 (giving 0.0018 lb), but since we're converting from a larger unit (tons) to a smaller unit (pounds), we must multiply. Remember that a ton is much heavier than a pound, so the number of pounds must be larger than the number of tons.
Question 9
A student walks 900 meters in 12 minutes. What is the walking rate in meters per second? Use 1 min=60 s.
- 75 m/s
- 1.25 m/s (correct answer)
- 0.8 m/s
- 4.5 m/s
Explanation: We need to find the walking rate in m/s from 900 meters in 12 minutes. First convert time: 12 min × (60 s/1 min) = 720 seconds. Then calculate rate: 900 m ÷ 720 s = 1.25 m/s. To verify: 900 ÷ 720 = 90 ÷ 72 = 1.25. A common error is dividing 900 by 12 without converting minutes to seconds first. Remember to convert time units before calculating rates when the desired unit involves seconds.
Question 10
A hiker walks 3.5 miles in 1.25 hours. Using 1 mile=5280 ft, what is the hiker's speed in feet per minute?
- 246.4 ft/min (correct answer)
- 88.7 ft/min
- 14,784 ft/min
- 4,620 ft/min
Explanation: We need to find the hiker's speed in feet per minute, given that they walk 3.5 miles in 1.25 hours. To set up the conversion, we'll use 1 mile = 5280 ft and 1 hour = 60 minutes. First, convert miles to feet: 3.5 miles × 5280 ft/mile = 18,480 ft. Next, convert hours to minutes: 1.25 hours × 60 min/hour = 75 minutes. Now divide distance by time: 18,480 ft ÷ 75 min = 246.4 ft/min. A common error is forgetting to convert both units or mixing up which number goes in the numerator versus denominator. When converting rates, always check that your final units match what's being asked for.
Question 11
A rectangular poster measures 24 inches by 18 inches. What is the area of the poster in square feet?
- 3 ft2 (correct answer)
- 36 ft2
- 2.5 ft2
- 432 ft2
Explanation: We need to find the area of a 24 inch by 18 inch poster in square feet. First, convert each dimension to feet: 24 in × (1 ft/12 in) = 2 ft and 18 in × (1 ft/12 in) = 1.5 ft. Then calculate the area: 2 ft × 1.5 ft = 3 ft². The key insight is that when converting area units, you must square the linear conversion factor: (1 ft/12 in)² = 1 ft²/144 in². A common mistake is converting only one dimension or forgetting to square the conversion factor. For area conversions, always convert linear dimensions first, then multiply.
Question 12
A rectangular garden measures 12 feet by 9 feet. What is its area in square inches?
- 15,552 in2 (correct answer)
- 1,296 in2
- 1,866,240 in2
- 108 in2
Explanation: We need to find the area of a 12 ft × 9 ft rectangle in square inches. First, find the area in square feet: 12 ft × 9 ft = 108 ft². To convert square feet to square inches, we must square the conversion factor: since 12 in = 1 ft, then (12 in)² = (1 ft)², so 144 in² = 1 ft². Therefore: 108 ft² × (144 in²/1 ft²) = 108 × 144 in² = 15,552 in². A critical error is using 12 instead of 144 as the conversion factor, forgetting that area conversions require squaring the linear conversion factor.
Question 13
A water tank holds 18 quarts. A manual describes capacity in gallons. Using 1 gal=4 qt, what is the tank's capacity in gallons?
- 3.6 gal
- 72 gal
- 4.5 gal (correct answer)
- 14 gal
Explanation: We need to convert 18 quarts to gallons. Set up the conversion: 18 qt × (1 gal/4 qt). The quart units cancel: 18/4 = 4.5 gallons. To divide: 18 ÷ 4 = 4 remainder 2, so 18/4 = 4 + 2/4 = 4 + 0.5 = 4.5. A common error is multiplying by 4 instead of dividing. Remember: gallons are larger than quarts, so converting quarts to gallons gives a smaller number.
Question 14
The weight of a package is 4 pounds. Convert this weight to ounces.
How many ounces are in 4 pounds?
- 32 oz
- 48 oz
- 80 oz
- 64 oz (correct answer)
Explanation: We need to convert 4 pounds to ounces using the US customary weight conversion factor. Set up the conversion: 4 pounds × (16 oz/1 pound). Calculate: 4 × 16 = 64 ounces, with the pound units canceling out properly. The crucial conversion factor is that 1 pound = 16 ounces in the US weight system. Students sometimes mistakenly use 12 (confusing with inches per foot) or 8 (half the correct value). Remember that weight conversions in the US system use 16 ounces per pound, unlike the more systematic factors of 10 in the metric system.
Question 15
You have a 12-foot long piece of wood. How many inches is this? (1 foot = 12 inches)
Convert 12 feet to inches.
- 72 inches
- 12 inches
- 144 inches (correct answer)
- 120 inches
Explanation: We need to convert 12 feet to inches using the given conversion factor of 1 foot = 12 inches. Set up the conversion using the provided factor: 1 foot = 12 inches. Using dimensional analysis: 12 feet × (12 inches/1 foot) = 144 inches. The feet units cancel out, leaving us with inches as our final unit. Students might confuse this with other conversions or divide instead of multiply. When converting from larger units (feet) to smaller units (inches), multiply by the conversion factor to get more of the smaller units.
Question 16
A movie lasts 2.25 hours. How many seconds is this? Use 1 hr=60 min and 1 min=60 s. Don't convert to minutes and stop.
- 8,100 s (correct answer)
- 13,500 s
- 7,500 s
- 135 s
Explanation: We need to convert 2.25 hours to seconds using two steps. First convert hours to minutes: 2.25 hr × (60 min/1 hr) = 135 min. Then convert minutes to seconds: 135 min × (60 s/1 min) = 8,100 s. Alternatively, chain the conversions: 2.25 hr × (60 min/1 hr) × (60 s/1 min) = 2.25 × 3,600 s = 8,100 s. A common error is stopping at 135 minutes or miscalculating 2.25 × 60. When dealing with decimals in time conversions, be extra careful with arithmetic.
Question 17
A map scale says 1 inch=4 miles. Two towns are 3.25 inches apart on the map. What is the actual distance between the towns in miles? (Do not convert inches to feet; the scale already relates inches to miles.)
- 0.8125 mi
- 7.25 mi
- 13 mi (correct answer)
- 52 mi
Explanation: We need to find the actual distance between towns that are 3.25 inches apart on a map with scale 1 inch = 4 miles. To convert map distance to actual distance, we multiply: 3.25 inches × (4 miles/1 inch) = 3.25 × 4 miles = 13 miles. The inch units cancel, leaving miles as our final unit. A common error would be dividing 3.25 by 4 (giving 0.8125 miles), but the scale tells us that each inch represents 4 miles, so we multiply. For map scale problems, multiply the map measurement by the scale factor to get actual distance.
Question 18
A hiking trail is 3.6 miles long. Using 1 mile=5,280 ft, how many feet long is the trail?
- 1,901 ft
- 19,008 ft (correct answer)
- 6,336 ft
- 57,024 ft
Explanation: We need to convert 3.6 miles to feet using the given conversion factor. Set up the conversion: 3.6 miles × (5,280 ft / 1 mile). Multiply: 3.6 × 5,280 = 19,008 feet, where the mile units cancel out leaving feet. A common error is confusing this with yards conversion (1 mile = 1,760 yards), which would give a much smaller answer. Always write out the units and conversion factors to avoid mixing up different conversions.
Question 19
A fish tank holds 15,000 mL of water. Convert this volume to liters using 1,000 mL=1 L. Which answer is correct?
- 0.015 L
- 1.5 L
- 15 L (correct answer)
- 150 L
Explanation: We need to convert 15,000 mL to liters using 1,000 mL = 1 L. Set up the conversion: 15,000 mL × (1 L / 1,000 mL). Divide: 15,000 ÷ 1,000 = 15 L, with mL units canceling. A common error is mishandling the thousands separator or decimal placement when dividing by 1,000. Remember that liters are larger than milliliters, so the numerical value should decrease.
Question 20
A square tile has side length 30 cm. What is the tile's area in square meters? Use 100 cm=1 m. (Area requires squaring the length conversion.)
- 0.9 m2
- 0.09 m2 (correct answer)
- 9 m2
- 900 m2
Explanation: We need to find the area of a 30 cm × 30 cm square in square meters. First find area in cm²: 30 × 30 = 900 cm². Then convert using (100 cm)² = 10,000 cm² = 1 m²: 900 cm² × (1 m² / 10,000 cm²) = 0.09 m². The key insight is that for area conversions, we must square the linear conversion factor: 100² = 10,000. A common error is using just 100 instead of 10,000 as the conversion factor.