The total number of problems she needs to grade is 6.
Answer:
1980
We can choose 2 men from 9 in 36 in ways.
We can choose 2 women from 11 in 55 ways.
For any arrangement of 2 men there are 55 ways of combining them with 2 women => 55 * 36 = 1980 total ways.
If you're wondering how i got the numbers i used the combination formula:
C(n, k) = 
Answer:
78
Step-by-step explanation:
x = your age
400 - 2x = 244
subtract 400 from both sides of the equation:
-2x = -156
divide both sides by -2:
x = 78