Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 26)
26.
A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :
Answer: Option
Explanation:
| (A + B + C)'s 1 day's work = | 1 | ; |
| 6 |
| (A + B)'s 1 day's work = | 1 | ; |
| 8 |
| (B + C)'s 1 day's work = | 1 | . |
| 12 |
 (A + C)'s 1 day's work |
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So, A and C together will do the work in 8 days.
Discussion:
53 comments Page 2 of 6.
Bhanu said:
1 decade ago
(A + B + C)'s 1 day's work = 1/6
(A + B)'s 1 day's work = 1/8
(B + C)'s 1 day's work = 1/12
so c's 1 day's work=1/6-1/8=1/24
and a's 1 day's work=1/6-1/12=1/12
and b's 1 day work=1/6(1/24+1/12)=1/4
so a and c 1'day work=1/12+1/24=1/8
(A + B)'s 1 day's work = 1/8
(B + C)'s 1 day's work = 1/12
so c's 1 day's work=1/6-1/8=1/24
and a's 1 day's work=1/6-1/12=1/12
and b's 1 day work=1/6(1/24+1/12)=1/4
so a and c 1'day work=1/12+1/24=1/8
Sk.Gopinath said:
1 decade ago
A+B+C = 1/6;
A+B = 1/8;
B+C = 1/12;
C's 1day work is =>1/6 - 1/8
=>1/24.
A's 1day work is =>1/6 - 1/12
=>1/8.
A+C 's 1day's work =>1/24 + 1/12.
= 1/8 = 8 days.
A+B = 1/8;
B+C = 1/12;
C's 1day work is =>1/6 - 1/8
=>1/24.
A's 1day work is =>1/6 - 1/12
=>1/8.
A+C 's 1day's work =>1/24 + 1/12.
= 1/8 = 8 days.
Jigme Wangchuk said:
5 years ago
Lcm of 8 and 12 =24.
A + B works 24/3 = 3 units.
B + C works 24/12 = 2 units.
A + B + C works 24/6 = 4 units.
Now, A works 4-2= 2 units.
C works 4-3= 1 units.
Total work done by A+C = 2+1= 3 units.
Therefore, 24/3= 8.
A + B works 24/3 = 3 units.
B + C works 24/12 = 2 units.
A + B + C works 24/6 = 4 units.
Now, A works 4-2= 2 units.
C works 4-3= 1 units.
Total work done by A+C = 2+1= 3 units.
Therefore, 24/3= 8.
(13)
Pranav Ambore said:
5 years ago
A+B+C=1/6 ---------> (1)
A+B=1/8 --------------> (2)
B+C=1/12-------------> (3)
By using(1) & (2).
1/8+c = 1/6.
c = 1/24.
By using(1) & (3).
A+1/12 = 1/6.
A = 1/12.
A + C = 1/12+ 1/24 = 1/8.
8 days.
A+B=1/8 --------------> (2)
B+C=1/12-------------> (3)
By using(1) & (2).
1/8+c = 1/6.
c = 1/24.
By using(1) & (3).
A+1/12 = 1/6.
A = 1/12.
A + C = 1/12+ 1/24 = 1/8.
8 days.
(19)
Nisha said:
1 decade ago
Why 2 is multiplied with 1/6.
To find out (A+C)'s work the equation is 2(A+B+C)-((A+B)+(B+C)).
On solving this equation,
A+B+C = 1/6;
A+B = 1/8;
B+C = 1/12;
(A+C)= 2(1/6)-(1/8+1/12),
= 1/8.
To find out (A+C)'s work the equation is 2(A+B+C)-((A+B)+(B+C)).
On solving this equation,
A+B+C = 1/6;
A+B = 1/8;
B+C = 1/12;
(A+C)= 2(1/6)-(1/8+1/12),
= 1/8.
Nik said:
1 decade ago
1 day's work of(A+B)=1/8
1 day's work of (B+C)=1/12
lets take 1 day's work of (A+C)=1/x
adding the above we get 2(A+B+C)=1/8+1/12+1/X
dr4 2(1/6)=(1/8)+(1/12)+(1/x)
1/x=(2/6)-(1/8)-(1/12)
1/x=1/8
1 day's work of (B+C)=1/12
lets take 1 day's work of (A+C)=1/x
adding the above we get 2(A+B+C)=1/8+1/12+1/X
dr4 2(1/6)=(1/8)+(1/12)+(1/x)
1/x=(2/6)-(1/8)-(1/12)
1/x=1/8
Parveen verma said:
1 decade ago
(A+B+C)=1/6
A's one day work work= (A+B+C)-(B+C)= 1/6-1/12 =1/12
C's one day work work= (A+B+C)-(A+B)= 1/6-1/8= 1/24
(A+C)'s one day work= 1/12+1/24= 1/8
so the work will be completed in 8 days
A's one day work work= (A+B+C)-(B+C)= 1/6-1/12 =1/12
C's one day work work= (A+B+C)-(A+B)= 1/6-1/8= 1/24
(A+C)'s one day work= 1/12+1/24= 1/8
so the work will be completed in 8 days
Pratiksha said:
2 years ago
A + B = 1/8.
B + C = 1/12.
A + B + C = 1/6.
C = A + B + C - A + B.
C = 1/6 - 1/8 = 1/24,
A = A + B + B - B + C,
A = 1/6 - 1/12 = 1/12
A + C = 1/12 + 1/24,
A + C = 1/8,
A + C = 8days.
B + C = 1/12.
A + B + C = 1/6.
C = A + B + C - A + B.
C = 1/6 - 1/8 = 1/24,
A = A + B + B - B + C,
A = 1/6 - 1/12 = 1/12
A + C = 1/12 + 1/24,
A + C = 1/8,
A + C = 8days.
(42)
ROHINI said:
1 decade ago
Given a+b=1/8, b+c =1/12, a+b+c =1/6, a+c =?
a+b+c = 1/6.
Sub a+b & b+c in above equ.
1/8 + c = 1/6.
c = 1/24.
a+1/12 = 1/6.
a = 1/12.
a+c = 1/12 +1/24 = 3/24 = 1/8.
a+b+c = 1/6.
Sub a+b & b+c in above equ.
1/8 + c = 1/6.
c = 1/24.
a+1/12 = 1/6.
a = 1/12.
a+c = 1/12 +1/24 = 3/24 = 1/8.
Nandhu said:
8 years ago
a+b=8,b+c=12,a+b+c=6.
LCM(8,12,6)=24.
a+b=24/8=3,b+c=24/12=2,a+b+c=24/6=4,
(a+b+c)-(a+b)=1,(a+b+c)-(b+c)=2,
c=1 a=2.
a+c=3,24/3=8.
ans:8.
LCM(8,12,6)=24.
a+b=24/8=3,b+c=24/12=2,a+b+c=24/6=4,
(a+b+c)-(a+b)=1,(a+b+c)-(b+c)=2,
c=1 a=2.
a+c=3,24/3=8.
ans:8.
(1)
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