B alone can complete a work in 30 days. A and B together can complete it in 20 days. In how many days can A alone complete the work?

40 days
50 days
60 days
70 days

Correct answer: 60 days

Solution

B’s one-day work = 1/30. A+B’s one-day work = 1/20. So A’s one-day work = 1/20 - 1/30 = 1/60, hence A alone takes 60 days.

Related IBPS PO Quantitative Aptitude questions

The ratio of work done by 30 women to the work done by 25 men in the same time is 5:6. If 9 women and 10 men can finish a work in 3 $\tfrac{1}{13}$ days, then how many women can finish the work in 4.5 days?
A certain number of men can complete a work in six hours less than the time taken by some women. Work completed by one man in one hour is the same as the work completed by one woman in one hour. Which of the following ratios of the number of men to the number of women can satisfy the given condition?
November: Each flat is supplied by a tap with a flow rate of 250 L/h, and only 50% of the flats are occupied in November. The water tank provides continuous water supply to these taps throughout the month. December: In this month, 30 flats are occupied and the tank gets emptied after 4$\tfrac{1}{6}$ days. The flow rate from one tap in December is A% more or less than the flow rate in November. January: The flow rate of water from the taps is the same as in November, and the tank gets emptied after supplying water to the building for 100 hours. The number of flats occupied in January is B%. In November, how many times does the tank need to be filled?
A can complete a task in 18 days, B can complete the same task in 24 days, and C can destroy the whole work in 36 days. If A and B work together for the first x days, and then C also joins them, the remaining work is completed in $x + 4\tfrac{4}{5}$ days. Find for how many days all three worked together.
Directions (74-78): Read the following information carefully and answer the question. x women can complete a piece of work in 2y days. 1.5x men can complete the same work in y days, while 2x children can complete the same work in 3y days. 2 women, 8 children and 8 men together can complete the same work in 22$\frac{1}{2}$ days. 9 men can complete the same work in $(y + 20)$ days. What is the value of y?
Directions (55–57): Read the following passage carefully and answer the questions given below. $p$ men can do a work in $q$ days and $q$ women can do the same work in $p$ days. If 20 men and 16 women can do the work together, they can complete the whole work in $53\tfrac{1}{3}$ days. 20 men and 24 women started working together and they did the work for $0.6x$ days, and $y$ boys did the remaining work in $0.45x$ days. If the whole work is completed in $x$ days by $y$ boys, then find the value of $x$.

⚔️ Practice IBPS PO Quantitative Aptitude free + battle 1v1 →