Answer : Given: ³⁵Cn+7 = ³⁵C4n–2 Need to find: Value of n We know, one of the property of combination is: If ⁿCr = ⁿCt, then, (i) r = t OR (ii) r + t = n Applying property (i) we

get, ⇒ n + 7 = 4n – 2 ⇒ 3n = 9 ⇒ n = 3 Applying property (ii) we get, ⇒ n + 7 + 4n – 2 = 35 ⇒ 5n = 30 ⇒ n = 6 Therefore, the value of n is either 3 or 6.