Question

To build a house at a faster pace, 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 laborer increased___$\%$

Answer 1

Solve using assumption

Lets say the number of hours / day initially = 10 and the wages = Rs 100 for 10 hours

Wages / hour =$\frac{100}{10}$= 10/hr

Earnings initially = 100 for 10 hours

New wages=$1.2\times 10$=12 / hr

New number of hours=$1.25\times 10$=12.5 hours

New earnings=$12\times 12.5$=150

$\%$change$\frac{50}{100}\times 100=50\%$ , Option (4).

2nd method:- $Wages\left(w\right)=No.ofhours\left(h\right)\times wages/hours\left(p\right)$

$\frac{W2}{W1}=\frac{h2\times p2}{h1\times p1}=1.25h1\times 1.2p1/h1\times p1=1.2\times 1.25=1.5$

F.O.M = 1.5 i.e $\%increases=50\%$. Option (4) .