Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 24)
24.
A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :
Answer: Option
Explanation:
Ratio of rates of working of A and B = 2 : 1.
So, ratio of times taken = 1 : 2.
| B's 1 day's work = | 1 | . |
| 12 |
 A's 1 day's work = |
1 | ; (2 times of B's work) |
| 6 |
| (A + B)'s 1 day's work = |  |
1 | + | 1 |  |
= | 3 | = | 1 | . |
| 6 | 12 | 12 | 4 |
So, A and B together can finish the work in 4 days.
Discussion:
28 comments Page 3 of 3.
Kapil said:
1 decade ago
Simple : A 's twice ie Half of B. . .So B is 1/12 thn Frm tis A is 1/12. . .thn A+B we get t Ans. . .
Mohit Rathore said:
2 years ago
16day * 20w = 16m * 15day.
320w = 240m.
4w = 3m,
M :W = 4 : 3.
( W= woman, M= Man).
320w = 240m.
4w = 3m,
M :W = 4 : 3.
( W= woman, M= Man).
Amrit said:
7 years ago
suppose B =x;
and A works twice =2x,
then the total amount of work is;
2x+x=12;
3x=12,
x = 4.
and A works twice =2x,
then the total amount of work is;
2x+x=12;
3x=12,
x = 4.
Inna Reddy Chilakala said:
10 years ago
A : B = 2 : 1 (work).
B = 12.
A can finish work 1 --- 12.
2 ---- 6.
A+B = 12*6/12+6 = 4.
B = 12.
A can finish work 1 --- 12.
2 ---- 6.
A+B = 12*6/12+6 = 4.
Uma said:
5 years ago
A=x, B = 2x.
1/x+1/2x = 1/12,
3/2x = 1/12,
3/6 = 2, x = 2.
so, B = 2x, 2 * 2 = 4.
1/x+1/2x = 1/12,
3/2x = 1/12,
3/6 = 2, x = 2.
so, B = 2x, 2 * 2 = 4.
(1)
Rajat pundir said:
7 years ago
a/b=2/1.
Now using the ratio method.
1/12=1/3*(a+b).
1/4=a+b.
Hence 4 days.
Now using the ratio method.
1/12=1/3*(a+b).
1/4=a+b.
Hence 4 days.
(1)
Paandu said:
1 decade ago
Why we are ratio this problem and ratio of times taken = 1:2 ?
Ashish said:
7 years ago
what is 1:2 here?
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