ACT Math : Other Decimals
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Example Questions
Example Question #173 : Decimals
Add:
Rewrite the problem so that the tenths, hundredths, and thousandths digits align. Use zeros as placeholders and solve.
Example Question #1 : Decimals
A runner runs 10.2 miles east, then 2.3 miles west, then 1.4 miles east.
How many miles did the runner travel from where he started? (How far east did the runner go)?
9.3 miles
6.5 miles
19.3 miles
13.9 miles
10.2 miles
9.3 miles
When the runner is travelling east, it's in the positive direction. West is the negative direction. So we can compute it by doing the operation 10.2 + (–2.3) + 1.4 = 9.3
Example Question #1 : Problem Solving
What is 
Example Question #2 : Problem Solving
Subtract:
Rewrite 
Example Question #301 : Arithmetic
If Exam 1 is worth 25% of the total grade, Exam 2 is worth 25% and Exam 3 is worth 50%, what is Dave’s final grade?
82
79
84
83.5
85.75
84
Final Grade = Exam1 * 0.25 + Exam 2 * 0.25 + Exam3 * 0.50 =
96*0.25 + 70*0.25 + 85*0.5 =
24 + 17.5 + 42.5 = 84
Example Question #12 : Other Decimals
A chemistry students needs to dilute some acid. How much water should be added to 2 L of 80% acid solution to yield 50% acid solution?
2.0 L
1.2 L
0.8 L
1.5 L
1.0 L
1.2 L
Pure water would be 0% solution and pure solution would be 100%
V1P1 + V2P2 = VfPf
Let x = amount of water to add
x(0) + 2(0.80) = (x + 2)(0.50) which when solved gives x = 1.2 L
Example Question #3 : How To Multiply And Divide Decimals
Kevin is looking at the blueprint of the house he is building. The scale is 1 inch = 5 feet. On paper, the master bedroom is 2.5 inches by 3 inches. What is the actual size of the bedroom?
20 ft x 30 ft
12.5 ft x 15 ft
7.5 ft x 9 ft
15 ft x 25 ft
10 ft x 10 ft
12.5 ft x 15 ft
The given dimensions must be multiplied by 5, so 2.5 inches becomes 12.5 feet, and 3 inches becomes 15 feet.
Example Question #1371 : Act Math
If 
Using the factor-label method we get the following equation.
We treat the units as if they are numbers, and can cancel the units from the fractions.
Example Question #3 : How To Multiply Decimals
A car has gas mileage of 46 miles per gallon. Assume that gas costs $3.90 per gallon. What would be the total cost of gas if the car traveled 1,150 miles?
$179.40
$100.00
$115.60
$125.70
$97.50
$97.50
First find out how many gallons of gas the car consumed while traveling 1150 miles. This can be found out like so:
1150 miles x gallons/46 miles = 25 gallons
Multiplying 25 by $3.90 yields $97.50.
Example Question #1 : How To Multiply Decimals
Evaluate
First,
Then,
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