Answer:

Given,

Sum of four terms is 50.

Assume these four terms as a – 3d, a – d, a + d, a + 3d

Sum of these terms –

4a = 50

a = 50/4

= 25/2 … (i)

It is also given that the greatest number is 4 time the least

a + 3d = 4(a – 3d)

Substitute the value of a = 25/2,

(25+6d)/2 = 50 – 12d

30d = 75

d = 75/30

= 25/10

= 5/2 … (ii)

Hence, the terms of AP are a – 3d, a – d, a + d, a + 3d which is 5, 10, 15, 20