Two cubes have their faces painted either red or blue. The first cube has five red faces and one blue face. When the two cubes are rolled simultaneously, the probability that the top faces of two cubes shows the same colouris 12 . Then number of red faces on the second cube is

Given the number of red faces on the 1st  cube is 5The number of blue faces on the 1st cube is 1Let the number of red faces on the 2nd cube is xThe number of blue faces on the 2nd cube is 6-xProbability of getting red face on 1st cube is 56Probability of getting blue face on 1st cube is 16Probability of getting red face on 2nd cube is x6Probability of getting blue face on 2nd cube is 6−x6Required probability PRR or BB=12⇒P(RR)+P(BB)=12⇒56⋅x6+16⋅6−x6=12⇒5x+6−x=18⇒4x=12⇒x=3Therefore, the correct answer is (3).