Freeze the coins puzzle #shorts

Freeze drying is

There are three coins one is a two-headed coin having head on both faces , another is a biased , coin that coines up tails 25% of the times and third is an unbiased coin. One of the three coins is chosen at random and tossed, it shows head what is the probability that it was a two-headed coin ?

The coin is notating with a plate without sliding If the coefficient of friction between the coin and plane is mu = 0.75 the friction between the coin and plate is If the plate is rotating along and the coin is gently placed on the rotating plate, the frictional force on the coin is

Consider the 3 -puzzle problem shown in figure.