If the coefficients of three consecutive terms in the expansion of $( 1 + x ) ^ { n }$ are in the ratio $1 : 5 : 20$ then the coefficient of the fourth term is (1) 2436 (2) 5481 (3) 1827 (4) 3654
If the coefficients of three consecutive terms in the expansion of $( 1 + x ) ^ { n }$ are in the ratio $1 : 5 : 20$ then the coefficient of the fourth term is\\
(1) 2436\\
(2) 5481\\
(3) 1827\\
(4) 3654