Question

64.
A, B and C go walking round a circle 1
km in circumference at the rates of 10m/
min, 20m/min and 40m/min respectively.
If they all start together and walk in the
same direction, when will they be
together at the same place?
(a) after 50 min (b) after 100 min
(c) after 240 min (d) after 800 min​

Answer 1

Answer:

Step-by-step explanation:A B and C cycling round a circle 1 km in circumference at the rate of 10 ,20 and 40 m/min respectively.

Hence in the same time if A completes makes one round, B will complete 2 rounds and C will complete 4 rounds to meet at the same place again.

Time taken by C to make four rounds = 4 x 1000/40 = 100 minutes

If they all start together in the same direction when will they again be together at the same place after 100 minutes when C would have completed 4 rounds, B 2 rounds and A 1 round.

Answer 2

Answer:

after 100 minutes

Step-by-step explanation:

if in the same time A will complete one full round

and B will complete two full round and c will complete four full round

time taken by C to take four rounds = 4× 1000/ 40