CMAT 2015 Solved Question Paper

(a ) Given, log 2 = 0.30103
Number of digit in ${25}^{10}$ = ?
We have, log${25}^{10}$ =10 log$5^2$ =2 x 10 Iog 5 = 20 log 5
= 20 log $\frac{10}{2}$ $\left[\because \log \frac{\mathit{m}}{\mathit{n}}=\log \mathit{m}-\log \mathit{n}\right]$
= 20 [log 10 - log 2] = 20[1 - 0.30103]
= 20 [0.69897] = 13.9794 ≃ 14
Hence, the number of digits in 2510 is 14.