Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 17)
17.
A is 30% more efficient than B. How much time will they, working together, take to complete a job which A alone could have done in 23 days?
Answer: Option
Explanation:
Ratio of times taken by A and B = 100 : 130 = 10 : 13.
Suppose B takes x days to do the work.
Then, 10 : 13 :: 23 : x  x = |
 |
23 x 13 |  |
x = |
299 | . |
| 10 | 10 |
| A's 1 day's work = | 1 | ; |
| 23 |
| B's 1 day's work = | 10 | . |
| 299 |
| (A + B)'s 1 day's work = | |
1 | + | 10 | |
= | 23 | = | 1 | . |
| 23 | 299 | 299 | 13 |
Therefore, A and B together can complete the work in 13 days.
Discussion:
119 comments Page 7 of 12.
Ramiz Raja said:
9 years ago
Let B takes x days to complete.
Therefore acccording to question,
1/x + 0.3/x = 23.
=> x = 23 * 1.3.
Now, (A + B)'s work 1/23 + 1/(23 * 1.3) = 1/13.
Hence required days = 13 days.
Therefore acccording to question,
1/x + 0.3/x = 23.
=> x = 23 * 1.3.
Now, (A + B)'s work 1/23 + 1/(23 * 1.3) = 1/13.
Hence required days = 13 days.
Bhishma said:
8 years ago
A is 30% effi then B.
So B=100%
A=130% take ratio=A/B=130/100=13:10
A:B
A, 13=1/23
B, 10=B cross xly
13B=10*1/23
B=10/23*13
B=10/299
A+B=1/23+10/299=1/13 days.
So B=100%
A=130% take ratio=A/B=130/100=13:10
A:B
A, 13=1/23
B, 10=B cross xly
13B=10*1/23
B=10/23*13
B=10/299
A+B=1/23+10/299=1/13 days.
SAITEJA VOTARIKARI said:
2 years ago
A = 130 %
B = 100%
Per day A's work = 1.3
Per day B's work = 1.
Together means 1 + 1.3 = 2.3.
So,
2.3 = 23
1.3 =?.
By cross multiplication, we get the answer 13.
B = 100%
Per day A's work = 1.3
Per day B's work = 1.
Together means 1 + 1.3 = 2.3.
So,
2.3 = 23
1.3 =?.
By cross multiplication, we get the answer 13.
(24)
Arun said:
9 years ago
A is 30% more efficient than B --A=1.3B.
A's 1 day work=1/23
Since A=1.3B
B's 1day work= 1/(1.3*23)=1/29.9.
A+B 's 1day work= (1/23+1/29.9)=1/13.
So 13 days.
A's 1 day work=1/23
Since A=1.3B
B's 1day work= 1/(1.3*23)=1/29.9.
A+B 's 1day work= (1/23+1/29.9)=1/13.
So 13 days.
Kranthi said:
9 years ago
Shortcut and Easy Method.
A work - 100 % - 23
B work - 130 %.
130/100 * 23 = 299/10,
A + B 1 day work = 1/23 + 10/299,
13 + 10/299 = 23/299 = 1/13,
13 Days.
A work - 100 % - 23
B work - 130 %.
130/100 * 23 = 299/10,
A + B 1 day work = 1/23 + 10/299,
13 + 10/299 = 23/299 = 1/13,
13 Days.
Naveen said:
3 years ago
A-> ( 100% = 23).
B->(130% = x).
Cross multiple:
100x = 23×130.
x = 23×130/100,
x = 299/10.
A + B-> 1/23 + 10/299.
13+10/299.
23/299.
Ans->13.
B->(130% = x).
Cross multiple:
100x = 23×130.
x = 23×130/100,
x = 299/10.
A + B-> 1/23 + 10/299.
13+10/299.
23/299.
Ans->13.
(25)
Siddharth said:
8 years ago
Answer is 10 people.
If a is 30% efficient than b. then,
Days ratio should be
a:b = 100:130, and a=1/23.
Solving this we get,
b = (13/230).
a+b = 10.
If a is 30% efficient than b. then,
Days ratio should be
a:b = 100:130, and a=1/23.
Solving this we get,
b = (13/230).
a+b = 10.
SK.Gopinath siva said:
1 decade ago
For those who stuck in solving the final step.
= 1/23 + 10/299.
= 1/23 (1/1 +10/13).
= 1/23 (13+10/13).
= 1/23 (23/13) =23/299 = 1/13 = 13.
= 1/23 + 10/299.
= 1/23 (1/1 +10/13).
= 1/23 (13+10/13).
= 1/23 (23/13) =23/299 = 1/13 = 13.
AMAN said:
6 years ago
The answer is approx 13 days.
As B would do the work in 230/7 days.
B's one day work would be 7/230.
a+b = x{1/23+7/230}=1.
x = apprx 13 days.
As B would do the work in 230/7 days.
B's one day work would be 7/230.
a+b = x{1/23+7/230}=1.
x = apprx 13 days.
Arunkumar said:
9 years ago
A=30% more efficient than B.
Assume B = 1 so A = 1.3(one day work) So 23*1.3 = 29.9(total work).
a+b = 1+1.3 = 2.3.
==> 29.9/2.3 = 13 days.
Assume B = 1 so A = 1.3(one day work) So 23*1.3 = 29.9(total work).
a+b = 1+1.3 = 2.3.
==> 29.9/2.3 = 13 days.
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