Question
The average age of A and B is 14 years. If A is to be
replaced by C, the average would be 13 years. The average age of C and A is 15 years. Find the age of A.Solution
A + B = 2 × 14 = 28 yr B + C = 2 × 13 = 26 yr C + A = 2 × 15 = 30 yr On adding all three, 2 (A + B + C) = 28 + 26 + 30 = 84 ⇒ A + B + C = 42 ∴ A = (A + B + C) – (B + C) = 42 – 26 = 16 yr
What will come in place of (?) question mark in the given number series.
12, 27, 44, 65, ?, 139
124, 107, 91, ? , 62, 49
257, 399, 566, ?, 983, 1237Â
12   18   31   51   ?   112
37, 57, 82, ?, 147, 187
41, 82, ?, 984, 4920, 29520Â Â Â
What will come in place of the question mark (?) in the following series?
4, 3, 7, 26, 101, ?
15, 31, 67, 131, ?, 375
- What will come in place of the question mark (?) in the following series?
121, 115, 102, 82, 55, ? 188    178    158   ?     88    38