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:
202 comments Page 6 of 21.
Varun bansal said:
1 decade ago
I can suggest a new method:
6 men + 8 boys = 10 days
=> 60 men + 80 boys = 1 day
=> 30 men + 40 boys = 2 days - eq.1.
But given that
26 men + 48 boys = 2 days - eq.2.
From one and two eqns.
4 men = 8 boys.
i.e. 1 man = 2 boys.
From eqn 1. 100 boys = 2 days.
50 boys = 4 days.
30 boys + 20 boys = 4 days.
15 men + 20 boys = 4 days.
6 men + 8 boys = 10 days
=> 60 men + 80 boys = 1 day
=> 30 men + 40 boys = 2 days - eq.1.
But given that
26 men + 48 boys = 2 days - eq.2.
From one and two eqns.
4 men = 8 boys.
i.e. 1 man = 2 boys.
From eqn 1. 100 boys = 2 days.
50 boys = 4 days.
30 boys + 20 boys = 4 days.
15 men + 20 boys = 4 days.
Suresh C B said:
1 decade ago
I have More smarter way to solve this.
6 Man and 8 Boys takes 10 days.
15 Man And 20 boys are 2.5 time more than 6 man and 8 boys so, this man and boys group takes 2.5 times less TIME 10/2.5 = 4.
6 Man and 8 Boys takes 10 days.
15 Man And 20 boys are 2.5 time more than 6 man and 8 boys so, this man and boys group takes 2.5 times less TIME 10/2.5 = 4.
Pradeep Oram said:
1 decade ago
@Sidharth.
There is also mentioned 2nd eq. i.e 26x+48y = 1/2.
And it doesn't relate to 3rd eq.
It may your procedure is quite wrong?
There is also mentioned 2nd eq. i.e 26x+48y = 1/2.
And it doesn't relate to 3rd eq.
It may your procedure is quite wrong?
V nirmal kumar said:
1 decade ago
6 men and 8 boys are in the ratio 6:8=3:4.
15 men and 20 boys are also in the same ratio 15:20=3:4.
Common factor for the first combination is 2 and common factor for the second combination is 5.
So if it take 10 days for the first combination then.
5 : 2.
10 : ?
= 4.
As you can see the common factors are in the ratio of the number of days needed to finish the work.
15 men and 20 boys are also in the same ratio 15:20=3:4.
Common factor for the first combination is 2 and common factor for the second combination is 5.
So if it take 10 days for the first combination then.
5 : 2.
10 : ?
= 4.
As you can see the common factors are in the ratio of the number of days needed to finish the work.
Zoya said:
1 decade ago
M1*D1/W1 = M2*D2/W2.
14[men + boys]*10 /1 = 35 * D2 /1.
14*10/35 = D2.
D2 = 4.
14[men + boys]*10 /1 = 35 * D2 /1.
14*10/35 = D2.
D2 = 4.
PRAVEEN K PILLAI said:
1 decade ago
6 men X 10= 60
8 men X10 = 80 i.e 60m = 80b.
So 1 men = 4/3 boys, So 6 men = 6 x 4/3-8 boys.
So 8+8 = 16 boys completes work in 10 days.
Now the case of 15 men and 20 boys.
15 men = 15 x 4/3 = 20 boys, So 15 men and 20 boys = 40 boys.
If 16 boys can do a work in 10 days then 40 boys will be able to do in 16 x10/4 = 4 days.
8 men X10 = 80 i.e 60m = 80b.
So 1 men = 4/3 boys, So 6 men = 6 x 4/3-8 boys.
So 8+8 = 16 boys completes work in 10 days.
Now the case of 15 men and 20 boys.
15 men = 15 x 4/3 = 20 boys, So 15 men and 20 boys = 40 boys.
If 16 boys can do a work in 10 days then 40 boys will be able to do in 16 x10/4 = 4 days.
Vikram sihag said:
1 decade ago
6m+8b = 10 days.
60m+80b =1 day eq.1.
15m+20b = ? eq.2.
Because eq.1 is 4 times eq.2, So ans is 4 days.
60m+80b =1 day eq.1.
15m+20b = ? eq.2.
Because eq.1 is 4 times eq.2, So ans is 4 days.
Akash kumar said:
1 decade ago
A and B can do a work in 12 and B and C in 16 days.
If A does work for 5 days and B for 7 days and then remaining work is completed by C in 13 days then C can Do this work in how many days?
If A does work for 5 days and B for 7 days and then remaining work is completed by C in 13 days then C can Do this work in how many days?
BLM said:
1 decade ago
We can solves these types of question by using simple formula: M1*D1 = M2*D2.
6M+8B =10D......1.
26M+48B =2D.....2.
15M+20B +?......3.
M1DI + M2D2.
From eq 1 and 2.
(6M+8B)*10 = (26M+48B)*2.
By solving we get,
1M=2B.
Now from eq 1 and 3, use the same formula. Substitute the value of man of boy.
(6M+8B)*10 = (15M+20B)*D2.
(6M+4M)*10 = (15M+10M)*D2.
D2 = 4 days.
6M+8B =10D......1.
26M+48B =2D.....2.
15M+20B +?......3.
M1DI + M2D2.
From eq 1 and 2.
(6M+8B)*10 = (26M+48B)*2.
By solving we get,
1M=2B.
Now from eq 1 and 3, use the same formula. Substitute the value of man of boy.
(6M+8B)*10 = (15M+20B)*D2.
(6M+4M)*10 = (15M+10M)*D2.
D2 = 4 days.
Ramya said:
1 decade ago
If they give 'or' instead of 'and' means we have to take + only.
Ex: 6 men and 8 boys.
6 men or 8 boys.
Ex: 6 men and 8 boys.
6 men or 8 boys.
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