Question

It is proposed to build a single circular park equal in area to the sum of areas of two circular parks of diameters $16m$ and $12m$ in a locality. The radius of the new park could be

• A. $10m$
• B. $15cm$
• C. $20m$
• D. $24cm$

Answer 1

The correct option is A $10m$

Let the radius of new park be r.

$\therefore \pi r^2=\pi (8{)}^2+\pi (6{)}^2$

$=>{\pi }^{r}2=64\pi +36\pi$

$=>\pi r^2=100\pi$

$=>r=10m$