Choosing 4 men from seven can be done in 7C4 = 35 ways
(There are 7 to choose from then 6 and 5 and 4 = 7 x 6 x 5 x 4
but we don’t want them in order so we need to divide by 4! = 4 x 3 x 2 x 1)
Similarly choosing 4 women from 11 can be done in 11C4 = 330 ways.
Total number of ways to choose 4 men and 4 women = 35 x 330 = 11550
I'll do part (a) to get you started.
The angle 'a' pairs up with the 123 degree angle as a corresponding angle pair. Due to the parallel lines, the corresponding angles are congruent. Therefore a = 123.
We also see that b = 123 as well since a = b (they are vertical angles).
Notice how angle c is adjacent to the 123 degree angle. These two angles form a straight line, so they must add to 180 degrees.
c+123 = 180
c = 180-123
c = 57
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To summarize, we have these three angles
a = 123
b = 123
c = 57
Hmmmmmm
Let me think for a second