**Age of 4 Brothers are as follow:**

1st - 70 Inches

2nd - 72 inches

3rd - 74 inches

4th - 80 inches

Let 1st be a, 2nd be b, 3rd be c & 4th be d

a = a

b = a+2

c = b+2 = a+2+2

d = c+6 = a+2+2+6

Thus,

74=(a+b+c+d)/4

74=(a+a+2+a+2+2+a+2+2+6)/4

74=(4a+16)/4

74=a+4

a=70.

Thus,

b = a+2 = 70+2 = 72

c = a+2+2 = 70+2+2 = 74

d = a+2+2+6 = 70+2+2+6 = 80.