Question

Shreya cycles to her school at an average speed of 12km/hr. It takes her 20 minutes to reach the
school. If she wants to reach her school in 15 minutes, what should be her average speed?

(a) 15 km/hr

(b) 16 km/h

(c) 18 km/hr

(d) none of these
​

Answer 1

Answer:

16km/h

Step-by-step explanation:

$Distance=speed*time$

$Speed=12km/hr\\\\Time=20min=\frac{20}{60} =\frac{1}{3}$hr

$Distance=12*\frac{1}{3} =4km$

$Speed=\frac{Distance}{Time}$

$Time=15min=15/60=\frac{1}{4} hr$

$Speed=\frac{4}{\frac{1}{4}}=\frac{4}{\frac{1}{\frac{1}{4}}}=\frac{4}{1}*\frac{4}{1} =16km/hr$

Option b is correct