Answer to Question #328078 in Statistics and Probability for robot

Question

Rohini has 3 scarfs which are identical in shape, form and cloth material. They are only different in colours. The first scarf is coloured red on both sides while both the sides of second scarf are coloured black. The third scarf is coloured black on one side and red on the other. She mixes the 3 scarfs in a box and randomly selects one scarfs and puts it down on the ground. If the upper side of the selected scarf is red in colour, what is the probability of the other side of the scarf to be black?

Answer 1

The fact that upper side of scarf is red means that either first or third scarf is selected.

There are 4 possible sides to select from two of these scarfs: 2 sides of 1'st scarf and 2 sides of 3'd scarf. Among these sides there is only one colored black. Probability of selecting it is 1 / 4 = 0.25 = 25%