Question

Given:$\log 2=0.3010$ and $\log 3=0.4771$, find the value of $\log 25$.

Answer 1

Given $\log 2=0.3010$ and $\log 3=0.4771$

$\log 25=\log (5\times 5)$

$=\log 5+\log 5$

$=\log \left(\frac{10}{2}\right)+\log \left(\frac{10}{2}\right)$

$=\log 10-\log 2+\log 10-\log 2$

We know $\log 10=1$

Substituting the values

$=1-0.3010+1-0.3010$

$=2-0.6020$

$=1.398$