Solving Equations: Isolate Variables to Find Unknowns

A store sells pencils for $2 each and erasers for $3 each. If you buy a total of 10 items and spend $24, how many pencils and erasers did you buy?

• 6 pencils and 4 erasers

• 4 pencils and 6 erasers

• 7 pencils and 3 erasers

• 5 pencils and 5 erasers

Maria has twice as many marbles as John. If John has x marbles and together they have 30 marbles, how many marbles does each person have?

• John has 5 marbles and Maria has 25 marbles.

• John has 15 marbles and Maria has 15 marbles.

• John has 12 marbles and Maria has 18 marbles.

• John has 10 marbles and Maria has 20 marbles.

A car rental company charges a flat fee of $50 plus $0.20 per mile driven. If you want to spend a total of $70, how many miles can you drive?

• 150 miles

• 50 miles

• 200 miles

• 100 miles

In a class, the number of boys is 5 more than twice the number of girls. If there are g girls in the class, how many boys are there?

• 2g + 5

• g - 5

• 3g - 2

• g + 5

A gardener is planting flowers in two different sections of a garden. The first section has 3 times as many flowers as the second section. If the total number of flowers is 48, how many flowers are in each section?

• First section: 36 flowers, Second section: 12 flowers

• First section: 40 flowers, Second section: 8 flowers

• First section: 30 flowers, Second section: 18 flowers

• First section: 24 flowers, Second section: 24 flowers

A book costs $15 and a magazine costs $5. If you buy a total of 8 items and spend $70, how many books and magazines did you buy?

• 2 books and 6 magazines

• 3 books and 5 magazines

• 1 book and 7 magazines

• 4 books and 4 magazines

A recipe requires 2 cups of flour and 3 cups of sugar. If you want to make a batch that uses 12 cups of flour, how much sugar will you need?

• 18 cups of sugar

• 12 cups of sugar

• 15 cups of sugar

• 10 cups of sugar

A concert ticket costs $30 and a VIP pass costs $50. If you buy a total of 5 tickets and spend $200, how many of each type did you buy?

• 5 concert tickets and 0 VIP passes

• 3 concert tickets and 2 VIP passes

• 2 concert tickets and 3 VIP passes

• 1 concert ticket and 4 VIP passes

A swimming pool is being filled with water. The pool can hold 500 gallons, and it is currently filled with 200 gallons. If water is being added at a rate of 10 gallons per minute, how long will it take to fill the pool?

• 30 minutes

• 40 minutes

• 20 minutes

• 50 minutes

A farmer has chickens and cows. If the number of cows is 3 more than twice the number of chickens and there are a total of 15 animals, how many chickens and cows does the farmer have?

• 4 chickens and 11 cows

• 6 chickens and 9 cows

• 3 chickens and 12 cows

• 5 chickens and 10 cows