Note 1 : All the persons worked on the job X for whole number days.
Note 2 : Two jobs Y and Z are similar to job X and require same effort as required by job X.
E worked on job 'Z' for 5 dyas and the remaining job was completed by A, B and D who worked on alternate days starting with A followed by B and D in thet order. Find the no. of days B worked for ?

Options

A. 2
B. 4
C. 9
D. 3

Answer

D

Explanation

Part of work completed by `E=(5)/(20)=(1)/(4)`
3 days work by `(A+B+D)=(1)/(10)+(1)/(12)+(1)/(18)`
`=(14+15+10)/(180)=(43)/(180)`
9 days work `(3A+3B+3D)=(129)/(180)`
Remaining work `=(3)/(4)-(129)/(180)`
`=(135-129)/(180)=(6)/(180)=(1)/(30)`
This will be done by A in `=(1)/(30)xx10=(1)/(3)` days
So B worked for 3 days.