Question

A alone can do a work in 40 days and ratio of efficiency of B to that of A is 5:4. If A started and worked for 15 days and left then then in how many days will B do the remaining work?

Answer 1

Answer:

Step-by-step explanation:

A completes in 40 days.

So in 1 day A completes 1/40 th part.

Given the ratio of time taken by A & B for completion of the work is 5:3.

So B will take 40×3/5=24 days to complete the work.

In 1 day B will complete 1/24 th part .

In 1 day both A & B together will complete 1/40+1/24=(24+40)/960=64/960=1/15 th part. So both A & B together will take 1÷1/15=15 days to complete the entire work.

Ans: 15 days.

Answer 2

Answer: 20 Days

Step-by-step explanation:

Given,

• A alone can complete a piece of work in 40 days.
• Ratio of efficiency of work of B to that of A is 5:4.
• A started to work on a piece and left after 15 days.

To Find: The number of days in which B will complete the remaining part of the work that A left after working for 15 days.

Explanation:

• First, we will calculate the number of days in which B alone can complete the same piece of work that A can complete in 40 days by using the efficiency ratio mentioned in the question-statement.

        Since Ratio of efficiency of work of B to that of A is 5:4, it means that [5:4::40:x], assuming B complete a piece of work in "x" days.$5:4::40:x\\or, \frac{5}{4} =\frac{40}{x} \\or, x=\frac{40*4}{5} \\or, x=(8*4)\\or, x=32$

[Note: Higher effeciency of work means less time to finish a piece of work]

• Therefore, B can finish the same piece of work that A can complete in 40 days in 32 Days.

• Then using the Unitary Method, we will calculate the piece of work A and B can individually complete in one day.

        If A can finish in 40 days, 1 whole work,

       Then, A can finish in 1 day, (1/40) part of the work.

       Similarly,  If B can finish in 32 days, 1 whole work,

       Then, B can finish in 1 day, (1/32) part of the work.

• Now, as per the question-mentioned condition, A left after working at his own rate for 15 days, i.e.,

        A finished $(\frac{1}{40}*15)=\frac{15}{40}=\frac{3}{8}$ part of the work and left.

• B finished the remaining part of the work, working at his own rate.
• Remaining part of the work = $(1-\frac{3}{8})=\frac{8-3}{8} =\frac{5}{8}$ part.
• Since, B can finish 1 whole work in 32 days,

        Then, B can finish (5/8) part of the work in $(32*\frac{5}{8})=(4*5)=20$ days.

A can do a work in 15 days and B in 20 days. If they work together on it for 4 days, what fraction of work will be left?

https://brainly.in/question/6500281

A can do a work in 24 days A and B together can finish the work in 6 days then B alone can finish the work in ____ days ?

https://brainly.in/question/15162587

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