Question
‘A’ alone can complete a work in 20 hours. ‘A’
started the work alone and left after working on it for 15 hours. If ‘B’ completed the rest of the work in 20 hours then find the time taken by ‘A’ and ‘B’ together to complete the whole work.Solution
Let the total work = 240 units Then, efficiency of ‘A’ = (240/20) = 12 units/hour Work completed by ‘A’ alone in 15 hours = 12 × 15 = 180 units Remaining work = 240 – 180 = 60 units So, efficiency of ‘B’ = 60/20 = 3 units/hour Therefore, combined efficiency of ‘A’ and ‘B’ = 3 + 12 = 15 units/hour So, time taken by ‘A’ and ‘B’ together to complete the work = (240/15) = 16 hours
What value should come in the place of (?) in the following number series?
192, 96, 96, 144, ?, 7201500 150 30 ? 3.6 1.8
What will come in place of the question mark (?) in the following series?
45, 88, 261, 1300, ?
86, 127, ?, 209, 250, 291
7, 6, 10, 27, 104, ?
37, 49, 63, ?, 97, 117
The question below is based on the given series I. The series I satisfy a certain pattern, follow the same pattern in series II and answer the questions...
12, 11, 20, 57, 224, 1015
What will come in place of the question mark (?) in the following series?
60, 110, 224, 463, ?, 1716
13, 29, 65, 129, ?, 373
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