Question

A earns rs. 80 in 7 hours and P rs. 90 in 2 hours. The ratio of their earnings is??

Answer 1

A earnings in 7 hours = Rs 80 

Earning per hour = $\frac{80}{7}$

P earning in 2 hours = Rs 90

Earning per hour = $\frac{90}{2}$

Ratio of earnings per hour = $\frac{80}{7} : \frac{90}{2}$
                                        
                                           = $\frac{8}{7} : \frac{9}{2}$
 
                                           = 16 : 63   [ by cross multiplication]

Answer 2

A earns Rs.80 in 7 hours.
A earns Rs.80/7 In 1 hour.
P earns Rs.90 in 2 hours.
P earns Rs.90/2 in 1 hour.
Since both the quantities are in the same units now,
A's earning:P's earning=80/7:90/2
=80/7*7:45*7=80:315=80/5:315/5=16:63
Answer:The required ratio is 16:63