Answer:
A
Step-by-step explanation:
Answer
the first one A the second one B
Step-by-step explanation:
A= a+b over 2 times height
18 + 8 = 26
26 divide by 2 = 13
13 x 6 = 78
area is 78
Answer:
28, 56
56
Step-by-step explanation:
a
To solve this, we use the combination rule.
nCk = n!/k!(n-k)! where
n is the number of options (8) k is the number of slots (2).
Assuming the order doesn't matter, then
8C2 = 8! / 2!(8-2)!
8C2 = 8! / 2! 6!
8C2 = 40320 / 2 * 720
8C2 = 40320 / 1440
8C2 = 28
If the order does matter, then we use permutation instead.
nPk = n!/(n-k!) where n = 8 and k =2 8P2 = 8! / 6!
8P2 = 40320 / 720
8P2 = 56
b
We are told that there exist 8 ways to choose a president and a vice president. This means that, after choosing a president from 8 people, there remains 7 people to choose his vice from. Thus, the number of ways to choose a president and his vice are 8 * 7 = 56
