Rapid Fire Round | Can she answer this in 30 seconds?

A and B start running at the same time and from the same point around a circle. If A can complete one round in 40 seconds and B in 50 seconds, how many seconds will they take to reach the starting point simultaneously ?

A body completes one round of a circle of radius R in 20 second. The displacement of the body after 45 seconds is

A telephone bill costs Rs 35.50 for 3 minutes 20 seconds. What is the cost, in rupees, for 5 minutes 30 seconds? (Round up to one decimal).