How to solve and set up a word problem?

Question

Lucy has money in a savings account.  If she withdraws $50 each month from this account, in 9 more months she will have  only 1/4 as much as she has today.  How much money is in Lucy's account today?

Answer 1

m is the amount of money she has in the account now.  If she withdraws $50 for 9 mos, that can be represented as (9*50).  The total (m) after $450 has been taken out is (equals) 1/4 of m.

 

m-(9*50)=1/4m

m-450=1/4m

m-1/4m=450

3/4m=450

m=(450*4)/3

m=600

 

Check your work:

600-450=150

Is 150 (the amount that remained) a quarter of 600 (the amount Lucy started with)?

150/600= 1/4, so this is correct.