# Math

posted by .

Can you help me with this problem?

At the beginning of January, Lisa had some money in her savings account. Each month she was able to deposit enough from her allowance to double the amount currently in the account. However, she had a loan to pay off, requiring her to withdraw \$10 from the account monthly. At the end of May, she had \$2 left in the account. How much did Lisa have at the beginning of January?

• Math -

At the beginning of January, Lisa had some money in her savings account. Each month she was able to deposit enough from her allowance to double the amount currently in the account. However, she had a loan to pay off, requiring her to withdraw \$10 from the account monthly. At the end of May, she had \$2 left in the account. How much did Lisa have at the beginning of January?

It depends on when the money was doubled, before or after the \$10.00 was paid out.
One way:
Jan.1--\$X
Feb.1--\$2X - 10
Mar.1--\$(4X - 20) - 10 = (4X - 30)
Apr.1--\$(8X - 60) - 10 = (8X - 70)
May 1--\$(16X - 140) - 10 = (16X - 150)

16X - 150 = 2 or X = \$9.50

The other way:
Jan.1--\$X
Feb.1--\$(X - 10)2
Mar.1--\$[(X - 10)2 - 10]2
Apr.1--I'll let you finish this one.

Jan.1st \$X
Feb.1st 2X - 10
Mar.1st

• Math -

thanks

## Similar Questions

1. ### College level math

Suppose you deposit \$100 in an account that earns 0.5% each month. You make no withdrawals from the account and deposit no more money into the account. How much money will you have in the account after 4 years?
2. ### economics

Jesse and Kimberly recently graduated from college and are starting a family. Currently, they are just making ends meet with their \$45,000 salary. They want to contribute the maximum amount (currently \$2,000) to fully fund an Educational …
3. ### Math

If you deposit P dollars into a bank account paying an annual interest rate r, with n interest payments each year, the amount A you would have after t years is A=P(1+r/n)^nt. Kevin places \$100 in a savings account earning 6% annual …
4. ### Foundations Math 12

Mark wants to buy a car in 15 months, when he graduates. He estimates the car he wants will cost \$12 500. Mark has just invested \$7500 in a GIC earning 4% compounded quarterly. He also has a savings account that earns 2.45%, compounded …
5. ### Math

(a) Themba wants to deposit a sum of money into a savings account so that he will have R30 000 in 3 years time for an overseas holiday how much money must he deposit into the account if the interest paid on the savings is 8,5% p.a …
6. ### Math

the amount of simple interest earned in a savings account varies directly with the amount of money in the savings account with the amount of money in the account. A certain bank offers a 2% savings rate write a direct variation equation …
7. ### math

Nathan deposited 7/9 of his allowance into his savings account. He spent the remaining amount, or \$2.50. How much did Nathan deposit into his savings account?
8. ### Math

At the beginning of the summer Molly decided to add a little money into her savings account every week. After seven weeks her account had \$175. At the end of 15 weeks her account had \$375. Assumed that she put the same amount of money …
9. ### Math

Jimmy opens a savings account with a \$200 deposit at the beginning of the month. The account earns 4.6% annual interest compounded monthly. At the beginning of each subsequent month, Jimmy deposits an additional \$200. How much will …
10. ### Algebra

I don't understand how to do this problem: A savings account is started with an initial deposit of \$500. The account earns 1.5% interest compounded annually. (a) Write an equation to represent the amount of money in the account as …

More Similar Questions