A sum was put at S.I. at a certain rate for 3 years. Had it been put at `4%` higher rate of interest, it would have fetched Rs. 120 more. Find the sum?

Explanation

Let the required sum be Rs. P and original rate is `R%`.
`therefore` New rate of interest = `(R + 4)%`
From the question, `because(Pxx(R + 4)xx3)/100 – (PxxRxx3)/100 =120`
`rArr (PxxRxx3)/100 + (Pxx4xx3)/100
– (PxxRxx3)/100= 120`
`rArr (Pxx4xx3)/100 = 120`
rArr `P = (120 xx 100)/ (4 xx 3)`
`therefore` P = Rs.1000
Hence, Required sum = Rs. 1000