A alone can do a peace of work in 7 days and B alone can do the work in 8 days . if both of them work together, how long will they take to complete the work ?
A 48/11
B 56 days
C 56/15 days
D none of these
PLEASE TELL
Answers
Answer:
Option C is correct.
Step-by-step explanation:
Let whole work be 1
Given:
In 7 days A alone can do 1 piece of work.
In 1 day A can do 1/7 part of work
In 8 days B alone can do 1 piece of wok
IN 1 day B can do 1/ 8 part of work.
Part of work completed by A and B in 1 day when they work together.
= (1/7) + )1/8)
=[(1 × 8 ) + ( 1 × 7)} /56
= (8 +7 ) /56=15 /56 part of work.
No. of days they will take to complete the work= whole work /part of work they completed in 1 day
= 1 / (15 /56)= 56/ 15 days
Answer:
Correct option is (c)= 56 /15 days
Step-by-step explanation:
According to the information provided in the question it is given as
A alone can do 1 piece of work= 7 days
B alone can do 1 piece of wok = 8 days
We need to find the time they will take if work together
A can do 1/7 part of work=1/7
Similarly
B can do 1/ 8 part of work=1 /8
By making a simple formula of work completion by A and B when they work together
= (1/7) + )1/8)
Simplifying the fraction we get
=[(1 × 8 ) + ( 1 × 7)} / 56
= (8 +7 ) /56=
=15 /56 part of work.
Number of days to complete the work= whole work /part of work they completed in 1 day
= 1 / (15 /56)= 56/ 15 day
Hence correct option is (c)= 56 /15 days