Can someone help me plzz

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Aclassroom is made up of 11 boys and 14 girls. the teacher has four main classroom responsibilities that she wants to hand out to four different students (one for each of the four students). if the teacher chooses 4 of the students at random, then what is the probability that the four students chosen to complete the responsibilities will be all boys?