Hogwarts School of Witchcraft and Wizardy sorted 150 new stu

Hogwarts School of Witchcraft and Wizardy sorted 150 new students into one of the four houses as follows: Gryffindor 44, Raven claw 40, Huffelpuff 35, and Slytherin 31. what would the sum of the expected values for Gryffindor and Raven claw be?

Solution

As there are 44+40 = 84 for Raven and Gryffindor, then if 1/4 of them will go to one house.

Thus,

1/4 of 84 = (1/4)*84 = 21 [ANSWER]