#
A and B can complete a piece of work together in 5 days. If A works at bwice his speed and B at half of his speed, the work can be finished in 4 days. How many days would it take for A alone to complete the work?

1
Log in to add a comment

Log in to add a comment

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

A can do work in X number of days

B can do work in Y number of days

Per day they can do: 1/X + 1/Y together.

in 5 days : 5/X + 5/Y. = total Work amount

2 * 1/X + 1/2 * 1/B = work per day after they change their speeds

4 * (2/X + 1/2*B) = total work = 5/X + 5/Y

1/X * 3 = 1/Y * 3 => X = Y

Hence the total work = 1/X * 5 + 1/X * 5 = 10 * 1/X

number of days for A to complete alone: (10/X) / (1/X) = 10 days

B can do work in Y number of days

Per day they can do: 1/X + 1/Y together.

in 5 days : 5/X + 5/Y. = total Work amount

2 * 1/X + 1/2 * 1/B = work per day after they change their speeds

4 * (2/X + 1/2*B) = total work = 5/X + 5/Y

1/X * 3 = 1/Y * 3 => X = Y

Hence the total work = 1/X * 5 + 1/X * 5 = 10 * 1/X

number of days for A to complete alone: (10/X) / (1/X) = 10 days