SOLUTION: Hello, Yasmin has some money. She spends $180 on a TV. She spends 3/10 of the remainder on a new printer. She has 2/5 of the money left at the end. How much money did Yasmin ha

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Hello, Yasmin has some money. She spends $180 on a TV. She spends 3/10 of the remainder on a new printer. She has 2/5 of the money left at the end. How much money did Yasmin ha      Log On


   

Question 1162073: Hello,
Yasmin has some money. She spends $180 on a TV. She spends 3/10 of the remainder on a new printer. She has 2/5 of the money left at the end. How much money did Yasmin have at the start
I am working backwards
3/5=.6
7/10=.7
.6 * .7 = .42
180/.42=428.57
The correct answer is $420.
I don’t know where I’m going wrong.
How would I setup the equation and solve.
Thanks in advance



Answer by ikleyn(52780) About Me  (Show Source):
You can put this solution on YOUR website!
.

Let x be the amount she had at the start.


After buying the TV, the remainder is  (x-180)  dollars.


3%2F10  of this remainder, i.e.   0.3*(x-180)  dollars, was spent for a new printer.


The new remainder is  0.7*(x-180).


It is equal to  2%2F5x = 0.4x.


So, your equation is


    0.4x = 0.7*(x-180).


Simplify ans solve


    0.4x = 0.7x - 0.7*180

    0.7*180 = 0.7x - 0.4x

    0.7*180 = 0.3x

    x = %280.7%2A180%29%2F0.3 = %287%2A180%29%2F3 = 7*60 = 420.


ANSWER.  She had 420 dollars at the start.