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:
204 comments Page 15 of 21.
Shgfgh said:
1 decade ago
2x+3y = 1/10 ----- (1).
3x+2y = 1/8 ------ (2).
We want to find: 2x+1y = ?---- (3).
Any one can solve this.
3x+2y = 1/8 ------ (2).
We want to find: 2x+1y = ?---- (3).
Any one can solve this.
Deepak Patgar said:
1 decade ago
6 men and 8 boys.
15 men and 20 boys.
If we look at the data carefully they are in the ratio 1:2.5.
i.e. 6:15 and 8:20 are same as 1:2.5.
So the number of days required for 15 men and 20 boys will be 10/2.5=4 days.
(Note: this method can be applied only when the ratios are same).
15 men and 20 boys.
If we look at the data carefully they are in the ratio 1:2.5.
i.e. 6:15 and 8:20 are same as 1:2.5.
So the number of days required for 15 men and 20 boys will be 10/2.5=4 days.
(Note: this method can be applied only when the ratios are same).
Jabi Mir said:
1 decade ago
We have two equations; 6x + 8y = 1/10 & 26x + 48y = 1/2.
We can write them as' 60x + 80y = 1 ...(1) & 52x + 96y = 1 ...(2).
Since work is same, equation 1 = equation 2.
i.e, 60x+ 80y = 52x+ 96y => 60x-52x = 96y-80y => 8x = 16Y.
or x/y = 16/8 => x=2y, Now substitution value of x in = n(1).
60 x 2y + 80y =1 => 120y +80y = 1.
or, 200y = 1 or y = 1/200.
Similarly, Now we can calculate value of x by substituting value of Y in any equation above.
We can write them as' 60x + 80y = 1 ...(1) & 52x + 96y = 1 ...(2).
Since work is same, equation 1 = equation 2.
i.e, 60x+ 80y = 52x+ 96y => 60x-52x = 96y-80y => 8x = 16Y.
or x/y = 16/8 => x=2y, Now substitution value of x in = n(1).
60 x 2y + 80y =1 => 120y +80y = 1.
or, 200y = 1 or y = 1/200.
Similarly, Now we can calculate value of x by substituting value of Y in any equation above.
Atul1487 said:
1 decade ago
We can do this in single step.
6 men and 8 boys can do work in 10 days.
So 6m+8b=1/10.
So we have to find 15m+20b=?
6m+8b=1/10.
Divide each term by 2 in both side we get,
3m+4b=1/20.
And multiply each term with 5.
15m+20b=5*120.
15m+20b=1/4.
So answer is 4 days simple.
6 men and 8 boys can do work in 10 days.
So 6m+8b=1/10.
So we have to find 15m+20b=?
6m+8b=1/10.
Divide each term by 2 in both side we get,
3m+4b=1/20.
And multiply each term with 5.
15m+20b=5*120.
15m+20b=1/4.
So answer is 4 days simple.
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.
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.
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?
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.
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.
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.
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