Question

A boy goes to school with a speed of 45 km/h and comes back with a speed of 30 km/h. find his average speed?

A 39 km/hr. Correct Answer Incorrect Answer
B 36 km/hr. Correct Answer Incorrect Answer
C 35 km/hr. Correct Answer Incorrect Answer
D 30 km/hr. Correct Answer Incorrect Answer
E 32 km/hr. Correct Answer Incorrect Answer

Solution

Since the distance travelled by a boy (going to school and coming back from school) is equal. So, average speed = 2xy/(x + y) Average speed = (2 × 45 × 30)/(45 + 30) Average speed = (2 × 45 × 30)/75 = 36 km/hr.

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