Question

P,Q,R, and S can do a work individual in 10,20,30, and 40 days respective, P and Q do half of the work and remaining half is done by R and S together,in how many days work was finished

Answer 1

.............efficiency........ work
p- 10.....12
q-20.... 6................ total-120
r-30..... 4
s-40..... 3
P+q= 9 (12+6)2
r+s= 7/2 (4+3) /2
120×2/25( 9+7/2)
9.6days answer
hope this help you

Answer 2

Amount of work P can do in 1 day = 1/20

Amount of work Q can do in 1 day = 1/30

Amount of work R can do in 1 day = 1/60

P is working alone and every third day Q and R is helping him

Work completed in every three days = 2 × (1/20) + (1/20 + 1/30 + 1/60) = 1/5

So work completed in 15 days = 5 × 1/5 = 1

Ie, the work will be done in 15 days