Question:The difference between the compound interest and the simple interest on a sum of money for `2` years at `12 1/2%`per annum is Rs.`150`.The sum is :
A `Rs. 9000`
B `Rs. 9200`
C `Rs. 9500`
D `Rs. 9600`
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+ Answer
D
+ ExplanationLet the sum be Rs.x. Then,
`C.I = x (1 + 25/(2 xx 100))^2 - x`
`= (9/8 xx 9/8) x - x`
`= (17x)/64`.
`S.I = (x xx 25/2 xx 2 xx 1/100)`
`= x/4`
`(C.I.) - (S.I.) = ((17x)/64 - x/4)`
`= x/64`
`:. x/64 = 150`
`or x = 9600`.