Question

ques. if 33 untrained labourers can do a work in 15 days of 12 hr. each, how many trained labourers can do 50% more work in 11 days of 9 hr each ? (it may be assumed that it takes 2 trained labourers to do the work of 5 untrained labourers)

Answer 1

Solution:

Let total amount of work = x

→33 untrained labourers can do a work in 15 days of 12 hr. each.

→12 hour = 1/2 day

→33 U×(15/2)  = x  ------(1)

Increased work = x + 50 x/100= x+x/2= 3 x/2

Suppose number of trained workers = P

9 hours= 9/24 days =3/8 days

11 days = 33/8 days

p T × (33/8) = 3 x/2---------(2) here pT is total number of trained workers.  

Dividing (1) by (2), we get

→(33 U × 15/2) ÷ (p T×33/8)=2/3

→ 2 T = 5 U→ U = 2 T/5

→(60 ×2 T)/(5 p T)=2/3

→24 / p=2/3

→ 72 = 2 p

→ p= 72/2 = 36 trained workers

→2 trained labours = 5 untrained labours

→2 T = 5 U

→ 1 U= 2 T/5

Let p trained labourers can do 50% more work in 11 days of 9 hr each.

p×Trained labour = 33/8× (3 x/2)=99 x/16

→p T = 99 x/16

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