Question

If the first three terms of a proportion are 3, 5 and 21 respectively, then its fourth term is: A 21 B 35 C 15​

Answer 1

Answer:

35

Step-by-step explanation:

let the fourth term be = x

So, Numbers proportion are 3,5,21,x

According to proportionality,

Product of means = Product of extremes

3 : 5 :: 21 : x

then we get, 3/5 = 21/x

then do cross multiplication

then we get, 3x = 21*5

                     3x = 105

                       x = 105/3

                         x = 35