To do a certain task Bhuvan would take 3 times as long as Abir and Varun together; and Varun would takes 4 times as long as Abir and Bhuvan together. Three of them together can complete the task in 5 days. How much time is taken by Bhuvan and varun to complete the task?

14\frac{1}{2} \text{ days }

14\frac{1}{2} \text{ days }

13\frac{1}{3} \text{ days }

13\frac{1}{3} \text{ days }

Please login to submit your explanation

If 5 men and 5 women work together then they can finish a work in 5 days but if 5 women work alone then they take 40/3 more days than the time required by 5 men. Find efficiency of one woman is how much percentage less than one man?

PrepInsta Explanation

User Explanation

Once you attempt the question then PrepInsta explanation will be displayed.

Let the days taken by 5W = x and 5M = y.

One day work of 5W = \frac{1}{x} and that of 5M = \frac{1}{y}

\frac{1}{x} + \frac{1}{y} = \frac{1}{5}

5 (x + y) = xy --------(1)

x = \frac{40}{3}+y

3 (x – y) = 40 -------(2)

Multiplying eq 1 and 2

3 (x² – y²) = 8xy

Dividing by y²

\frac{3x^{2}}{y^{2}} - \frac{8x}{y} - 3 = 0

Let \frac{x}{y} = t

3t² – 8t – 3 =0

t = 3

So ratio of efficiency of W : M = 1 : 3

Efficiency of Women = 66.67% less than that of Men

Please login to submit your explanation

A can-do 3/5th of work in 15 days. The efficiency of B is 25% more than that of A. Both A and B started working together and left the work after five days. C completed the remaining work in 11 days. The efficiency of C is what percent more/less than that of A?

PrepInsta Explanation

User Explanation

Once you attempt the question then PrepInsta explanation will be displayed.

A does 3/5th of work in 15 days.

Time Taken by A to complete the work

=5\times \frac{15}{3} = 25 \text{ days }

Efficiency of B is 25% more than that of A.

If Work done by A in one day = 4, then work done by B in one day = 5

Ratio of time taken by A and B = 5 : 4

Time taken by B to complete the work

=4\times \frac{25}{5} = 20 \text{ days }

A and B worked for five days.

Total work Completed by A and B in 5 days

= 5 \left( \frac{1}{25} + \frac{1}{20} \right)<br />
=\frac{1}{5} + \frac{1}{4} = \frac{9}{20}

Work Left = \frac{11}{20} which is done by C in 11 days.

Time taken by C to complete the whole work =\frac{20}{11} \times{11}<br />
C = 20 days<br />
Ratio of Efficiency of A and C =\frac{20}{25}

Efficiency of C is 25 % more than that of A.

Please login to submit your explanation

Amit and Sujit together can complete an assignment of Data entry in 5 days. Sujit’s speed is 80% of Amit’s speed and the total key depressions in the assignment are 5,76,000. What is Amit’s speed in key depressions per hour if they work for 4 hours a day?

PrepInsta Explanation

User Explanation

Once you attempt the question then PrepInsta explanation will be displayed.

Amit + Sujit = 5 Days

Let Amit = x Days

Therefore, Sujit = \frac{80x}{100} = \frac{4x}{5} Days

Now,

[larex]\frac{1}{x} + \frac{5}{4x} = \frac{1}{5}[/latex]

x = \frac{45}{4}

∴ Amit = x = \frac{45}{4}, Sujit = x = \frac{45}{4}\times \frac{4}{5} = 9

∴ Ratio of their work = 5:4

∴ Required Key Depression per hour a day = \frac{5}{9}\times 576000\times \frac{1}{4}\times \frac{1}{5}

= 16000

Please login to submit your explanation

["0","40","60","80","100"]

["Need more practice!","Keep trying!","Not bad!","Good work!","Perfect!"]

Login/Signup to comment