Answer:

it takes 5 seconds for 15 m.

and 5m in first case.

Answer:

Let Distance=D; Speed= S and Time=T

In this case, Time T is the same.

Distance = Speed x Time or D= SxT

In the first case, D = 1 xT or D =T ——->(1)

In the second case, D + 15 = 3 xT or 3 T ——->(2)

Using value of D as per (1) in (2),

T +15 = 3 T or 2T =15 or T=15/2= 7.5 seconds

As D=S x T, Distance covered in first case = 1m/second x 7.5 second= 7.5 meters

(Also, Distance covered in 2nd case = 7.5 + 15 = 22.5 mteres)

Explanation:

i hope that this answer will be right