Basic Arithmetic : Basic Arithmetic

Study concepts, example questions & explanations for Basic Arithmetic

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Example Questions

Example Question #1 : Linear Equations With Ratios And Rates

I put  in a bank account at a  annual simple interest rate. How much interest will have accumulated after two years?

Possible Answers:

Correct answer:

Explanation:

This is a simple interest rate problem, for which we use the formula:

Interest = P x r x t

P is the principal, or original loan amount; r is the annual interest rate; and t is the number of years in question.

In this problem, P = $9,000; r = 4%; and t = 2 years. Plugging these into the formula gives us:

So, after two years the account has gathered $720 in interest.

Example Question #1 : Linear Equations With Ratios And Rates

If  painters can paint  houses in  day, how many painters would it take to paint  houses in  day?

Possible Answers:

Correct answer:

Explanation:

We can set up the following proportions using the given information:

Now, cross multiply these two fractions to get the following equation:

Divide both sides by .

Example Question #11 : Ratios And Rates

If a car travels at  miles per hour, how many hours would it take the car to travel  miles?

Possible Answers:

Correct answer:

Explanation:

We can write 40 miles per hour as the following fraction:

Since we want to figure out how many hours it takes a car to travel 200 miles, we can write the following equation:

Now, cross multiply.

Divide both sides by 40.

Example Question #1 : Linear Equations With Ratios And Rates

If one recipe calls for  eggs to make  waffles, how many eggs are needed to make  waffles?

Possible Answers:

Correct answer:

Explanation:

To solve this problem, we can set up a proportion.

That proportion will tell us how many eggs go into each waffle. Since the number of eggs that goes into each waffle doesn't change, we can set these two proportions equal to each other.

Now, fill it in with the information we know:

For the sake of making math easier, drop the words so we get the following equation:

To solve for x, cross-multiply this equation.

Divide both sides by 18.

Example Question #1 : Linear Equations With Ratios And Rates

The ratio of boys to girls in a class is . If there are  boys in the class, how many girls are in the class?

Possible Answers:

Correct answer:

Explanation:

We can write the following equation using the ratios given:

 is the number of girls in the class.

Now, we can cross multiply to get the following equation:

Now divide both sides by .

Example Question #2 : Linear Equations With Ratios And Rates

Jessica fills an aquarium with water. The aquarium can hold  gallons of water—it's a huge aquarium! The faucet fills the tank at a rate of 1 gallon every 10 seconds. How long (in seconds) will it take Jessica to fill the tank?

Possible Answers:

 

Correct answer:

 

Explanation:

The rate at which Jessica fills the tank can be written as a ratio:

Multiply this ratio by the total amount of gallons possible to get the amount of time it takes to fill the tank. 

Gallon units cancel out, so you are left with seconds as the final unit in the answer.

Example Question #1 : Other Ratios And Rates

A diving team swims in  competitions, and wins  overall competitions.  What is their lose to win ratio?

Possible Answers:

Correct answer:

Explanation:

A diving team that wins 6 competitions out of 10 will have 6 winning meets and 4 losing meets.  Therefore, their lose to win ratio is:

 

This can be reduced to:

Example Question #1 : Other Ratios And Rates

A soccer team wins  out of their  games.  What is their win to loss ratio?

Possible Answers:

Correct answer:

Explanation:

Since the soccer team has won 8 out of 10 games, they have 8 winning games and 2 losing games.  

Therefore, their win to loss ratio is:

This ratio can be reduced to:

Example Question #1 : Other Ratios And Rates

The sales tax rate at your favorite clothing store is . You buy a shirt for  and a hat for . What is the total amount, including tax, that you pay for your purchases?  

Possible Answers:

Correct answer:

Explanation:

First, you want to figure out the total cost of your purchase by adding up the price of all the items you are buying:

Then, you find the tax you will pay on this total by taking 7% of $35:

You add the cost of your purchase plus the tax to find the total amount that you have to pay:

 

Example Question #1 : Other Ratios And Rates

Joe takes home a  commission of his total sales at the furniture store. Yesterday he sold one  chair and two  chairs. How much money did he make from commission yesterday?

Possible Answers:

Correct answer:

Explanation:

First you find the total amount of sales that Joe made yesterday by adding the cost of each item he sold:

Joe sold $20,000 worth of furniture yesterday. He makes 15% commision, so we find 15% of 20,000:

Joe made $3,000 from commission yesterday.

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