6, 18, 3, 21, 7, 56, ?
8
9
63
64
Explanation:
Each term at an even place in the series is the product of its two adjacent terms.Thus, if the missing term be x, then we have : 7 x x = 56 or x = 56 ÷ 7 = 8.
Each term at an even place in the series is the product of its two adjacent terms.Thus, if the missing term be x, then we have : 7 x x = 56 or x = 56 ÷ 7 = 8.