Question

find time when:
S.I= 3500
rate% per annum=8%
principle=2500​

Answer 1

sl=prt/100

3500=2500×8×t/100

t=3500/100×2

35/2=17.5 years .

Answer 2

we know that

$t = i \times \frac{100}{p \times r} \\ 3500 \times \frac{100}{2500 \times 8} \\ 3500 \times \frac{1}{25 \times 8} \\ 140 \times \frac{1}{8} \\ \frac{35}{2} or \: \: 17.5 \: year$