Jayesh can do some work in 8 hrs. Rajesh can do the same work in 12 hrs. Brajesh can do it in x hrs.

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01 Feb 2022 Time and Work

Jayesh can do some work in 8 hrs. Rajesh can do the same work in 12 hrs. Brajesh can do it in x hrs. All three starts working at 11:30 am. While Jayesh stops working at 1:30 pm and the remaining two complete the work at 4 pm. Brajesh alone can finish the same work in ___ hours.

OPtion

1) 18
2) 15
3) 24
4) 10
5) 20
6) 36
7) 12
8) 9
9) 8
10) None of these

Solution

All three works together between 11:30 am to 1:30 pm i.e. for 2 hrs and only Rajesh & Brajesh works between 1:30 pm to 4 pm i.e. for 2 hrs 30 min.
.'. 2 hrs work of (Jayesh+Rajesh+Brajesh) + 2½ hrs work of (Rajesh+Brajesh) = 1
2*( 1/8 + 1/12 + 1/x) + (5/2)*(1/12 + 1/x) = 1
Solving we get x=12
Therefore, Brajesh alone can finish the same work in 12 hrs.

Correct Option: 7 Best Solution (2)

G.S.Kantharao   2 years AGO

(1/8 + 1/12 + 1/x)*2+(1/12 + 1/x) 5/2=1
(5x+24)2/24x+(x+12)5/24x=1
10x+48+5x+60=24x
9x=108=>x=12
My option is 7👈

Like? Yes (2) | No   

Mayank Kandoi   2 years AGO

Total work = T
Work done by Jayesh in 1 hour = T/8
Work done by Rajesh in 1 hour = T/12
Work done by Brajesh in 1 hour = T/x
2 (T/8) + 4.5 (T/12 + T/x) = T
x = 12
Option (7)

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