Question
The average weight of (n + 1) girls is 50 kg, and the
average weight of (n - 3) boys is 70 kg. If the overall average weight is 62 kg, how many boys are there?Solution
ATQ: [(n + 1) × 50 + (n - 3) × 70] ÷ [(n + 1) + (n - 3)] = 62 Or, 50n + 50 + 70n - 210 = 62 × (2n - 2) Or, 120n - 160 = 124n - 124 Or, 4n = - 36 Or, n = -9 Hence solution is impossible
4, 6, 12, 30, ?, 315, 1260Â
Find the missing term in the series:
1, 4, 9, 16, 25, ?, 49
36, 48, 24, 60, ?, 72
?, 15, 45, 225, 1575, 14175
What should come in place of (?) question mark in the given number series.
2, 6, 15, 31, 56, ?
10,14,26,42,70,?
53 × 38 + 32 × âˆ›54872 = ?
168, 164, 155, 139, ?, 78
18, 30, 46, 66, 90, ?
152    142    122   ?     52    2