Answer:
15/322
Step-by-step explanation:
There are 12 tests of test A, and there are 12 tests of test B.
For the student to get A, it is a 12/24 chance.
For the next student, it is a 11/23 chance
For the next 10/22
For the next 9/21
12/24*11/23*10/22*9/21=15/322
15/322 chance
no, h=7
9+9h = 10h+2
9=h+2
7=h
2^3×3^2
and yh
2×2×2×3×3