1.
25%
.3 + .2 + .15 + .1 = .75
1.00 - .75 = .25
2.
120 students
There are 400 total students
.3 * 400 = 120
4.
tennis-
.1 * 400 = 40 students prefer tennis
football-
.25 * 400 = 100 students prefer football
140 students like football/tennis
5.
400 students
There are four quarters in a whole
.25% = 100
100 * 4 = 400
