Question
‘A’ alone can complete a work in 15 days. ‘B’
alone can complete the same work in 20 days. If ‘A’ and ‘B’ work together for 5 days, then the remaining work can be completed by ‘A’ alone in how many days?Solution
Let the total amount of work = 60 units {LCM of 15 and 20} Then, efficiency of ‘A’ = 60/15 = 4 units/day Efficiency of ‘B’ = 60/20 = 3 units/day Combined efficiency of ‘A’ and ‘B’ = 4 + 3 = 7 units/day Work completed by ‘A’ and ‘B’ together in 5 days = 5 × 7 = 35 units Remaining work = 60 – 35 = 25 units Time taken by ‘A’ alone to complete the remaining work = 25/4 = 6.25 days
Find the missing number in the given number series.
6, 15, 35, 66, 108, ?11   6   7   12   26    ?    205.5
15, 23, 30, 36, 41, ?
- What will come in place of the question mark (?) in the following series?
-5, -2, ?, 10, 19, 30 What will come in place of the question mark (?) in the following series?
36, 85, ?, 230, 330, 451
- What will come in place of (?) in the given number series.
121, 100, 81, 64, ?, 36 7    12    34    117    ?   2465   14820
...Find the missing number in the given number series.
8, 9, 16, 11, 32, 13, ?Find the missing number in the given number series.
442, 424, 410, 400, 394, ?
16, 16, 32, 96, ?, 1920
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