To build a house at a faster place, the contractor increases the wages/ hour of each worker by 20% and the working hours by 25%. By how much percent has the daily earnings of each labourer increased?
Solve using assumption
Lets say the number of hours / day initially = 10 and the wages = Rs 100 for 10 hours
Wages / hour = = 10/hr
Earnings initially = 100 for 10 hours
New wages = 1.2 x 10 = 12 / hr
New number of hours = 1.25 x 10 = 12.5 hours
New earnings = 12 x 12.5 = 150
% change = x 100 = 50% , Option (4).
2nd method:- Wages(w)= no. of hours(h) x wages/hour(p)
W2/W1 = h2 x p2 / h1xp1 = 1.25h1 x 1.2 p1 / h1 xp1 = 1.2 x 1.25 = 1.5
F.O.M = 1.5 i.e % increase = 50% . Option (4) .