Question

Mrs.Tan spent 5/8 of her savings on a microwave oven and a refrigerator. Of the amount she spent,4/7 was used to pay for the refrigerator. The refrigerator cost 280$ more than the microwave oven. How much was Mrs. Tan's savings at first?

Answer 1

Let the amount of her saving be x
Cost of both = (5/8)x
Cost of fridge = (4/7)×(5/8)x = (5/14)x
(5/8)x-(5/14)x = 280
(L.C.M.of 8 and 14 is 56
(5×7/8×7)x-(5×4/14×4)x=280
(35/56)x-(20/56)x= 280
35x-20x/56=280
15x^56=280
x=1045.33
here saving were $1063.33
Cost of fridge =(5/14)×1045.33=373.33
Cost of both=5/8×1045.33=653.33
Difference = 653.33-373.33
= 280
m= microwave
r= refrigator
s=saving
m+r=5/8s
r=4/7×5/8s = 5/14s
r=5/14s
m=r-280
m=(5/14)s-280
m+r=5/8s
5/14s-280+5/14=5/8s
5/14s+5/14-5/8=280
10/112s=280
s= 112/10× 280
s=$3,136