Answer :

(I) 140 sec (2) 300 sec or 5 min

Step-by-step explanation:

(1)80+60=140

(2)1 lap is 60 sec or 1min

we multiply with 60 sec × 5 = 300 sec or

1 min ×5 = 5 min

Answer:

(i) 240 s

(ii) 20 min

Step-by-step explanation:

(i) Just look at the times for X and Y after each round, when is the first time, that the times match? In seconds

X:  60, 120, 180, 240 ...

Y:  80, 160, 240, ....

So they meet at the starting point after 240 seconds.

X has done 3 laps and Y 4 laps at this time.

(ii)

To answer this question: Let x be the number of laps that Y has done.

If X has done 5 laps more the following must be true:

60 * (x + 5) = 80x

60x + 300 = 80x

300 = 20x

x = 15

Therefore Y has done 15 laps at the time, which results in:

80 * 15 = 1200 seconds - or 20 min.

At the same time

60 * 20 = 1200 seconds gives the same outcome