Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 6)
6.
If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, the time taken by 15 men and 20 boys in doing the same type of work will be:
Answer: Option
Explanation:
Let 1 man's 1 day's work = x and 1 boy's 1 day's work = y.
| Then, 6x + 8y = | 1 | and 26x + 48y = | 1 | . |
| 10 | 2 |
| Solving these two equations, we get : x = | 1 | and y = | 1 | . |
| 100 | 200 |
| (15 men + 20 boy)'s 1 day's work = |  |
15 | + | 20 |  |
= | 1 | . |
| 100 | 200 | 4 |
15 men and 20 boys can do the work in 4 days.
Discussion:
201 comments Page 10 of 21.
Purushottam Kumar said:
10 years ago
(6m+8b)*10 = (26m+48b)*2.
=> (6m+8b)*5 = 26m+48b.
=> 30m+40b = 26m+48b.
=> 4m = 8b.
=> m = 2b.
=> m/b = 2x/x (let).
Now, total work = (6m+8b)*10.
=> (6*2x+8*x)*10.
=> 200x.
Now, (15m+20b)*n = 200X (where n is required number of days).
=> (15*2x+20*x)*n = 200x.
=> (50x)*n = 200x.
=> n = 4 days.
=> (6m+8b)*5 = 26m+48b.
=> 30m+40b = 26m+48b.
=> 4m = 8b.
=> m = 2b.
=> m/b = 2x/x (let).
Now, total work = (6m+8b)*10.
=> (6*2x+8*x)*10.
=> 200x.
Now, (15m+20b)*n = 200X (where n is required number of days).
=> (15*2x+20*x)*n = 200x.
=> (50x)*n = 200x.
=> n = 4 days.
Mishi said:
10 years ago
I can't understand how 10 days come 1/10? If anyone can explain it?
Naresh said:
10 years ago
2x+3y = 1/10 ----- (1).
3x+2y = 1/8 ------ (2).
2x+1y = ? ------- (3).
Answer: 12 1/2.
Is it right?
3x+2y = 1/8 ------ (2).
2x+1y = ? ------- (3).
Answer: 12 1/2.
Is it right?
Renju K S said:
9 years ago
@Meera.
Can you explain how you got 3/5 in RHS by multiplying with 6 to the 1st equation?
Can you explain how you got 3/5 in RHS by multiplying with 6 to the 1st equation?
Chinna said:
9 years ago
Sir please give a shortcut technique.
Poorva said:
9 years ago
3 men and 2 boys can complete a work in 16 days, while 2 men and 3 boys complete same work in 20 days. Then how much days will it takes to complete the same work with 2 men and 1 boy (work and time question from arihant book).
Viki said:
9 years ago
I'm too confused. Please give me shortcut method.
Aditi said:
9 years ago
Can you tell why we have taken 1/10 days in the above question's equation?
Varuni said:
9 years ago
Because their one day work will be 1\10.
While the total number of days to do the work = 10.
Solution :
2x + 3y = 1/10.
3x +2y = 1/8.
20x + 30y = 1.
24x + 16y = 1.
120x + 180y = 6.
120x + 80y = 5.
100y = 1.
y = 1/100.
x = 7/200.
While the total number of days to do the work = 10.
Solution :
2x + 3y = 1/10.
3x +2y = 1/8.
20x + 30y = 1.
24x + 16y = 1.
120x + 180y = 6.
120x + 80y = 5.
100y = 1.
y = 1/100.
x = 7/200.
Swati said:
9 years ago
You are genius @Siddharth.
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