Question

A and B start walking in the same direction at the same time around a circular park of diameter 4200 m. If A walks 10 m more than B in every minute with a speed of 5 km per hour, then they meet each other next time after A makes................ rounds. (ii) 8 (i) 7 (iii) 9 (iv) 10​

Answer 1

Va = 5000 m / 3600 s = 1.39 m/s

(Va - Vb) 60 = 10

Vb = Va - .167 = 1.22 m/s

(Va - Vb) T = 4200 Π where T is time for A to complete 1 more lap

.17 T = 4200 Π

T = 24700 Π time for A to again catch B

N = 1.39 * 24700 Answer:

Va = 5000 m / 3600 s = 1.39 m/s

(Va - Vb) 60 = 10

Vb = Va - .167 = 1.22 m/s

(Va - Vb) T = 4200 Π where T is time for A to complete 1 more lap

.17 T = 4200 Π

T = 24700 Π time for A to again catch B

N = 1.39 * 24700 Π / (4200 Π) = 8.2 laps

A will make 8 but not 9 rounds before catching B