Question
Present ages of ‘A’, ‘B’ and ‘C’ are in the
ratio 8:12:17, respectively. If present average age of ‘A’ and ‘C’ is 25 years, then find the age of ‘B’ when ‘C’ was 24 years old?Solution
Let the present ages of ‘A’, ‘B’ and ‘C’ be ‘8x’ years, ‘12x’ years and ‘17x’ years, respectively. ATQ; (17x + 8x) ÷ 2 = 25 Or, 25x = 50 So, x = 2 So, present age of ‘C’ = 17 × 2 = 34 years Present age of ‘B’ = 12 × 2 = 24 years Difference between the ages of ‘B’ and ‘C’ = 34 – 24 = 10 years So, age of ‘B’ when ‘C’ was 24 years old = 24 – 10 = 14 years
50 62 ? 96 126 138
...89Â Â Â Â Â 78Â Â Â Â Â 74Â Â Â Â Â 67Â Â Â Â Â 63Â Â Â Â ?
4 6 ? 31 119 601
...Find the maximum number of trees which can be planted, 25 meters apart, on the two sides of a straight road 2125 meters long
55 46 60 41 65 36 ?
8 6 2 ? -1 9.5
...9999 6666 ? 2962.66 1975.11 1316. 74
...2, 17, 147, 1167, 8157, 48957
3,   2,   3,  8,  31,  ?
Study the given pattern carefully and select the number that can replace the question mark (?) in it.
4 7 6
15 ? 21
44 68 60
