Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 29)
29.
A and B can do a job together in 7 days. A is 1
times as efficient as B. The same job can be done by A alone in :
times as efficient as B. The same job can be done by A alone in :Answer: Option
Explanation:
| (A's 1 day's work) : (B's 1 day's work) = | 7 | : 1 = 7 : 4. |
| 4 |
Let A's and B's 1 day's work be 7x and 4x respectively.
| Then, 7x + 4x = | 1 |  11x = |
1 | x = |
1 | . |
| 7 | 7 | 77 |
 A's 1 day's work = |
 |
1 | x 7 |  |
= | 1 | . |
| 77 | 11 |
Discussion:
53 comments Page 3 of 6.
Bharathi said:
8 years ago
It's easy to understand. Thanks @Kuntal.
Yashwanth said:
8 years ago
What will be the answer for same problem with A is twice the efficiency of B?
Swapna said:
8 years ago
7+4=11......28 ,7....? 11/7*28 = 44 ans.
Juhi said:
9 years ago
If 4/7 of a piece of work is completed in 7/4 days, in how many days can rest of the work be completed?
Heena said:
1 decade ago
@nidhi
if A=(7/4)B
then Eq2 should be
7/4(B)+B=1/7
if A=(7/4)B
then Eq2 should be
7/4(B)+B=1/7
Prabhu said:
8 years ago
Nice explanation @Jimmy John.
Varun said:
1 decade ago
Ratio type problem solve by 'x' value.
Nidhi said:
1 decade ago
A and B collectively can do the work in 7 days.
So their one day work is 1/7.
A+B=1/7-- (1).
A is 7/4 times efficient then B which means.
A= (7/4) B.
Or.
B= (4/7) A - (2).
Put the value of (2) in (1).
(4/7) *B+B=1/7.
B=1/11 THIS IS HIS ONE DAY WORK.
ALONE B CAN FINISH IN 11 DAY.
So their one day work is 1/7.
A+B=1/7-- (1).
A is 7/4 times efficient then B which means.
A= (7/4) B.
Or.
B= (4/7) A - (2).
Put the value of (2) in (1).
(4/7) *B+B=1/7.
B=1/11 THIS IS HIS ONE DAY WORK.
ALONE B CAN FINISH IN 11 DAY.
UMESH PRASAD said:
1 decade ago
A and B collectively can do the work in 7 days
so their one day work is 1/7
A+B=1/7-------(1)
A is 7/4 times efficient then B which means
A=(7/4)B ----------
or
B=(4/7)A ------------(2)
put the value of (2)in (1)
(4/7)*B+B=1/7
B=1/11 THIS IS HIS ONE DAY WORK
ALONE B CAN FINISH IN 11 DAY
so their one day work is 1/7
A+B=1/7-------(1)
A is 7/4 times efficient then B which means
A=(7/4)B ----------
or
B=(4/7)A ------------(2)
put the value of (2)in (1)
(4/7)*B+B=1/7
B=1/11 THIS IS HIS ONE DAY WORK
ALONE B CAN FINISH IN 11 DAY
Pankaj said:
1 decade ago
How Total Working Days=7*4=28 ?
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