Question

A boy covers a distance of 2.5 km in 15 minutes and the next 3 km in 18 minutes. What is the average
speed of the boy?​

Answer 1

Given :-

Distance covered in 15 min = 2.5 km

Distance covered is 18 min = 3 km

To Find :-

The average  speed of the boy.

Solution :-

We know that,

• s = Speed
• d = Distance
• t = Time

According to the question,

Distance₁ = 2.5 km + 3 km

= 5.5 km

By converting,

1 km = 100 m

= 550 m

Distance₂ = 15 min + 18 min

= 33 min

By converting,

1 minute = 60 sec

= 1980 sec

Using the formula,

$\underline{\boxed{\sf Speed = \dfrac{Total \ distance}{Total \ time} }}$

Given that,

Total distance (d) = 550 m

Total time (t) = 1980 sec

Substituting their values,

s = 550/1980

s = 2.77 m/s

Therefore, the average  speed of the boy is 2.77 m/s.

Answer 2

Given :-

Distance covered in 15 min = 2.5 km

Distance covered is 18 min = 3 km

To Find :-

The average speed of the boy.

Solution :-

We know that,

s = Speed.

d = Distance

t = Time

According to the question,

Distance₁ = 2.5 km + 3 km

= 5.5 km

By converting,

1 km = 100 m

= 550 m

Distance₂ = 15 min + 18 min

= 33 min

By converting,

1 minute = 60 sec

= 1980 sec

Using the formula,

Speed=

Total time

Total distance

Given that,

Total distance (d) = 550 m

Total time (t) = 1980 sec

Substituting their values,

s = 550/1980

s = 2.77 m/s

Therefore, the average speed of the boy is 2.77 m/s.