​Mridul's working hours per day increased by 25% and his hourly wages increased by 20%. By how much per cent did his daily earnings increase?

Correct option is C

Given:

Increase in Mridul’s working hours = 25%

Increase in hourly wage = 20%

Formula Used:

Successive Percentage =$$x+y = \frac{xy}{100}$$​​

Solution:

Let the working hours per day = 10

Let the hourly wage = 100

Then total daily earnings = 10 × 100= 1000

Increase in working hours = 10 + 25% of 10 = 12.5

Increase in hourly wage = 100 + 20% of 100 = 120

Total daily earning now = 12.5 × 120 = 1500

Increase in daily earning = 1500 - 1000 = 500

Percent increase =$$\frac{500}{1000}\times 100 = 50\%$$​​

Alternative Method:

Successive percent formlua =$$25 +20 + \frac{(25)(20)}{100}$$​​

= 45 + 5

= 50%