Question
A and B can complete a work in 20 and 30 days,
respectively. If they work together for 10 days and then A leaves, how many more days will B take to finish the work?Solution
A's work rate = 1/20 per day. B's work rate = 1/30 per day. Together, A and B’s combined work rate = 1/20 + 1/30 = 1/12 per day. In 10 days, they will complete: (1/12) × 10 = 5/6 of the work. Remaining work = 1 - 5/6 = 1/6. B alone can complete 1/30 of the work per day, so the time B will take to complete 1/6 of the work is: (1/6) ÷ (1/30) = 5 days. Correct option: a
2, 6, ?, 20, 30, 42
- What will come in place of the question mark (?) in the following series?
10, 17, 26, 37, 50, ? 41, 82, ?, 984, 4920, 29520Â Â Â
What will come in place of the question mark (?) in the following series?
72, 78, 90, ?, 132, 162
17, 19, 41, 127, 513, ?Â
156, 182, 210, 240, 272, ?
What value should come in the place of (?) in the following number series?
56, 28, 28, 42, 84, ?
654, 647, 633, 612, 584, ?
Find the missing number in the given number series.
?, 6, 30, 210, 1890, 18900
5, 23, 18, 36, 31, ?
