Question

In setting up a post 1/3 of its length is buried in the ground and 1/5 of the remainder is tarred and the rest being painted green what fraction of (1) the whole. (2) the part above the ground is green.

Answer 1

We know one-third of it is underground and one-fifth of it is the remainder and tarred. To find the whole:

$\frac{1}{3}+\frac{1}{5}=???$
⇒$LCM(3,5)=15$
⇒$\frac{1}{3}*\frac{5}{5}=\frac{5}{15}$
⇒$\frac{1}{5}*\frac{3}{3}=\frac{3}{15}$
⇒$\frac{5}{15}+\frac{3}{15}=\frac{8}{15}$

Therefore, the whole is 8/15.