It didn't get answered last time so I'm gonna try again.

a. 0%

b. 15%

c. 35%

d. 50%

a. 2/3

b. 3/2

Step-by-step explanation:

Given,

Male = 25%

Students who walk to school = 40 %

Remaining = 100% - ( 25 + 40 )%

                  = 100% - 65%

Remaining = 35%

Since, female is not given, so female = 0%

a. 0%

b. 40% - 25% = 15%

c. 35%

d.

Union : 15% + 35% = 50%

Intersection = 35% - 15% = 20%

Note : -

Union means adding ( + ).

Intersection means subtracting ( - ).

a.

Sum = 4

Total = 2 + 4 = 6

P = 4/6 = 2/3

b.

Sum = 8

Total = 2 + 6 + 4 = 12

P = 12/8 = 3/2