+58 Ali had a certain amount of savings in the bank. In October, he spent 30% of her savings. In November, he managed to save 1/5 of the amount of money he had left. Then, he bought 2 calculators at $15.80 each and gave 3/8 of the amount that he had left to his parents. In December, he managed to save 40% of the amount of money he had left. Finally, he had $6219.85 in the bank. (a) How much did he give to his parents? (b) How much was his original savings in the bank?
+128407 Call S the original amt
Amount left at the end of Oct = .7S
Amount left at the end of Nov = .7S / 5 = .14S
After buying two calculators and giving (3/8) of the money left to his parents he had
(.14S - 2(15.80)) - (3/8)[ .14S - 2(15.80) ] =
.14S - 31.60 - .0525S + 11.85 =
.0875S - 19.75 left
In Dec he had .40 [ .0875 S - 19.75 ] left
And this equals 6219.85
So
.40 [ .0875S - 19.75] = 6219.85
.0875S - 19.75 = 6219.85 /.40
.0875S -19.75 = 15,549.63
.0875S = 15,549.63 + 19.75
.0875S = 15,569.38
S = 15569.38/.0875 = $ 177,935.77
He gave his parents (3/8)[ .14 * 177935.77 - 31.60 ] = $9329.78
