Question:A sum of money trebles itself in `15` years `6` month. In how many years would it double itself ?
A `6` years `3` month
B `7` years `9` month
C `8` years `3` month
D `9` years `6` month
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+ Answer
B
+ ExplanationLet sum = x. Then,S.I.`= 2x &`Time `= 31/2` years
Rate` = ((100 xx 2x)/x xx 2/31)%`
`= (400/31)%`
:. Time` = ((100 xx x)/x xx 31/400)` years.
`= 7` years`9` month