Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 1)
1.
A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :
Answer: Option
Explanation:
| A's 1 day's work = | 1 | ; |
| 15 |
| B's 1 day's work = | 1 | ; |
| 20 |
| (A + B)'s 1 day's work = |  |
1 | + | 1 |  |
= | 7 | . |
| 15 | 20 | 60 |
| (A + B)'s 4 day's work = | |
7 | x 4 | |
= | 7 | . |
| 60 | 15 |
| Therefore, Remaining work = | |
1 - | 7 | |
= | 8 | . |
| 15 | 15 |
Discussion:
344 comments Page 1 of 35.
UMAKANT CHAUDHARY said:
1 month ago
To solve this type of question,if days are given and if we have to find together work finishing days then,
= (15+20)/15 * 20,
= 35/300,
= 7/60.
Now, in 4 days they can do 4 * 7/60,
= 7/15.
So, Remaining work = 1-(7/15).
= 8/15.
= (15+20)/15 * 20,
= 35/300,
= 7/60.
Now, in 4 days they can do 4 * 7/60,
= 7/15.
So, Remaining work = 1-(7/15).
= 8/15.
(12)
Pankaj Kushwah said:
1 month ago
The answer is 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3 = 7.
For 4 days = 4 * 7 = 28.
60 - 28 = 32.
32/60 = 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3 = 7.
For 4 days = 4 * 7 = 28.
60 - 28 = 32.
32/60 = 8/15.
(48)
SFG said:
2 months ago
Thanks for explaining the answer @Anjali thakur.
(6)
Anjali thakur said:
3 months ago
The answer is 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3=7.
For 4 days = 4 * 7=28.
60-28 = 32.
32/60 = 8/15.
Lcm of 15 and 20.
Then it will give you 60.
Now 60/15 = 4, 60/20 = 3.
Together for one day 4 + 3=7.
For 4 days = 4 * 7=28.
60-28 = 32.
32/60 = 8/15.
(49)
Guna said:
4 months ago
Agree, the answer is D.
(3)
Syam said:
6 months ago
@Sree.
15 is written as = 5 * 3 and 20 is written as 2^2 *5 then 5 is the common then from 15 take 3 and 20 take 2 square, then 4*3*5=60 then 1 * 4/15 * 4 = 4/60 and for 1/20 =1 * 3/20 * 3 = 3/60.
Then the final answer is 4/60 + 3/60 = 7/60.
15 is written as = 5 * 3 and 20 is written as 2^2 *5 then 5 is the common then from 15 take 3 and 20 take 2 square, then 4*3*5=60 then 1 * 4/15 * 4 = 4/60 and for 1/20 =1 * 3/20 * 3 = 3/60.
Then the final answer is 4/60 + 3/60 = 7/60.
(10)
Sajid said:
6 months ago
(+1-7/15).
(-*-=+) = 8/15.
(-*-=+) = 8/15.
(3)
Sravanthi tolusuri said:
6 months ago
LCM of 15,20 = 60
days * efficiency = work so, 15 * 4 = 60 20 * 3 = 60.
Efficiencies are 4+3 =7,
They worked for 4 days 7*4 =28.
Total work =60,
60 - 28 =32.
Then the remaining work = 32/60 = 8/15.
days * efficiency = work so, 15 * 4 = 60 20 * 3 = 60.
Efficiencies are 4+3 =7,
They worked for 4 days 7*4 =28.
Total work =60,
60 - 28 =32.
Then the remaining work = 32/60 = 8/15.
(116)
Sree said:
8 months ago
How 7/60 came? please anyone explain to me?
(33)
Irfan said:
11 months ago
How to find out the remaining work? Please explain.
(43)
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