the current estimation of eye color distribution in the unit

the current estimation of eye color distribution in the united states is a follows 40% brown 35% blue 12 % green 7% grey and 6% hazel

a- if four people are selected at random what is the probability two have brown eyes and two have blue eyes?

b- if four people are selected at random what is the probability that everyone had a different eye color?

please show with steps, thanks

Solution

a. if four people are selected at random then the probability two have brown eyes and two have blue eyes:0.4*0.4*0.35*0.35=0.0196

b. if four people are selected at random then the the probability that everyone had a different eye color is: 0.4*0.35*0.12*0.07*0.06=0.00007