Erwin flips a coin and rolls a standard number cube. Find the probability that the coin will show heads and the cube will show a multiple of 3.

flipping heads on a coin is a 1/2 chance, and multiples of three are 3 and 6, which is 1/3, thus, 1/2*1/3=1/5 there is a 1/5 chance Erwin will flip heads and roll a multiple of 3.