Samiara, Mahira and Kiara rented a set of DVDs at a rent of ? 578. If they used it for 8 hours, 12 hours and 14 hours respectively, what is Kiara's share of rent to be paid?

It is required to find the highest common factor of 5750 and 5000, because his daily wage is their common factor.
Hence, the daily wage is ? 250.

A can do a work in 12 days.
? Work done by A = 1/12
B can do a work in 16 days.
? Work done by A = 1/16
Ration of Work done by A : Ration of Work done by B = 1/12 : 1/16
Ration of Work done by A : Ration of Work done by B = 4 : 3
A's shares = 2100 x 4/7 = 300 x 4 = ? 1200
B's share = 2100 x 3/7 = 300 x 3 = ? 900

A, B and C contract to do a work for ? 4200. A can do the work in 6 days, B in 10 days and C in 12 days.
From given question, As we know that
A can do the work in 6 days.
A can do 1/6 work in one day.
B can do the same work in 10 days.
B can do 1/10 work in one day.
C can do the same work in 12 days.
C can do 1/12 work in one day.
Work done shared by A : B : C = 1/6 : 1/10 : 1/12
Multiply by 60, we will get,
Work done shared by A : B : C = 10 : 6 : 5
Let us assume ration variable is P.
According to question,
10P + 6P + 5P = 4200
? 21P = 4200
? P = 200
A's share = 10P = 10 x 200 = ? 2000
B's share = 6P = 6 x 200 = ? 1200,
C's share = 5P = 5 x 200 = ? 1000