et four numbers be a, b, c and d respectively. ∴ a + b + c + d = 48 ......(i) and, a + 5 = b + 1 = c – 3 = d – 7 = x (let) ∴ a = x – 5; b = x – 1, c = x + 3, d = x + 7 From equation (i), x – 5 + x – 1 + x + 3 + x + 7 = 48 ⇒ 4x + 4 = 48 ⇒ 4x = 48 – 4 = 44 ⇒ x =
44
4
= 11 ∴ a = x – 5 = 11 – 5 = 6 b = x – 1 = 11 – 1 = 10 c = x + 3 = 11 + 3 = 14 d = x + 7 = 11 + 7 = 18