Find the third proportional to 60 and 90.

Correct option is D

Given:

Two number are 60 and 90

Formula Used:

If the third proportional of two number a and b is c

Then a:b::b:c

Solution:

If the number a:b::c:d are in proportion then $$a \times d = b \times c$$​​

We have a:b::b:c = 60:90::90:c

​$$c= \frac{90 \times 90}{60} = 135$$​​