The velocity-time graphs of a car and a scooter are shown in the figure. (i) the difference between the distance travelled by the car and the scooter in 15s and (ii) the time at which the car will catch up with the scooter are, respectively.

The distance traveled in 15 seconds by both will be given by area under curve.
For car, s1 = 1/2 × 15 × 45
s1 = 337.5m
For scooter, s2 = 15 × 30
s2 = 450
s1 - s2 = 112.5m
Suppose after time t, they will meet, then distance traveled by both of them will be equal.
30t = 1/2 × 15 × 45 + 45 × (t - 15)
30t = 337.5 + 45t - 675
15t = 337.5
t = 22.5s