A traffic light runs repeatedly through the following cycle: green for 30 seconds, then yellow for 3 seconds,and then red for 30 seconds. Leah picks a random three-second time interval to watch the light. What is the probability that the colour changes while she is watching?

A complete cycle of a traffic light takes 60 s. During each cycle the light is green for 25 s, yellow for 5 s and red for 30 s. At a randomly chosen time, the probability that the light will not be green is

Kavita decorated her home beautifully with lights on Diwali. She had three strings of blinking lights with different light colours. The lights of first string remain off for 3 seconds, the second string for 5 seconds and the third string for 6 seconds. The time interval after which lights of the three strings will glow again after switching them on at the same time is:

The time period of a seconds pendulum is measured repeatedly for three times by two stop watches A,B. If the readings are as follows , then

A complete cycle of a traffic light takes 60s. During each cycle the light is green for 25s, yellow for 5s and red for 30s. At a randomly chosen time, the probability that the light will not be green , is a) 1/3 b) 1/4 c) 4/12 d) 7/12

A bag contains 4 red and 5 black balls, a second bag contain 3 red and 7 black balls. One ball is drawn at random from each bag, find the probability that the ball are of the same colour.

A bag contains 4 red and 5 black balls, a second bag contain 3 red and 7 black balls. One ball is drawn at random from each bag, find the probability that the ball are of the same colour.

Anurn contains 6 red,4 blue ,2 green and 3yellow marbles If three marbles are picked at random, what is the probability that two are blue and one is yellow?