Question

You have $35 in your bank account and deposit $2.50 each week. At the same time, your cousin has $115 but is withdrawing $7.50 each week. When will the accounts have the same balance? How much will they have?

What are the variables and equations, and how do you solve?

Answer 1

$55

Explanation:

Let w = the no. of weeks

35 + 2.50w = amount you will have in the account after w weeks

115 - 7.5w = amount cousin will have in the account after w weeks

You need to set these expressions equal to each other.

35 + 2.50w = 115 - 7.5w Multiply thru the equation

by 10 to remove the fractions

350 + 25w = 1150 - 75w

100w = 800

w = 8 weeks

35 + 2.50w = 35 + 2.5(8) = 35 + 20 = $55

115 - 7.50w = 115 - 7.50(8) = 115 - 60 = $55