word problem

[user948123]

How do I solve the word problem: Mary, Lindsey and Sara all have the same amount of money. If they add Rachel's $15 to their money, they will have $105. How much money does Mary have?

 

[soroban]

Hello, user948123!

Mary, Lindsey and Sara all have the same amount of money.
If they add Rachel's $15 to their money, they will have $105.
How much money does Mary have?

Are you really having trouble with these problems?


The three girls have \(\displaystyle \text{THIS}\) amount of money.

If $15 is added to \(\displaystyle \text{THIS}\), the total is $105.

So, we know that \(\displaystyle \text{THIS}\) must be $90 . . . (or do you follow that?)


Since the three girls have equal amounts of money, each one must have: \(\displaystyle \$90 \div 3 \:=\:\$30\)