Answer:
0.2601
Step-by-step explanation:
There are 19C16 = 969 ways for Lester to choose 16 of the 19 objects.
There are 12C11 = 12 ways to choose 11 vases, and 7C5 = 21 ways to choose a non-vase, for a total of (12)(21) = 252 ways to choose exactly 11 vases in 16 objects.
So, the probability of interest is ...
252/969 ≈ 0.2601
_____
nCk = n!/(k!(n-k)!) ... the number of ways to choose k objects from n
Step-by-step explanation:
f(0) = ( f(k) +f(-k) ) / 2
f(0) = (16 - 4) / 2
f(0) = 12 / 2
f(0) = 6 → ANSWER
*Remember that f(0) = m(0) + n = n
If we have f(x) = mx + n, then:
f(k)= mk + n and f(-k)= -mk + n
If we add them:
f(k) + f(-k)
= mk + n -mk + n
= 2n
= 2f(0)
So we conclude that:
f(0) = [f(k) + f(-k)] / 2
Answer: 12.75 inches
Step-by-step explanation:
Let x represent last year's rainfall.
Multiply by 0.8 since this year was 20% less.
x(0.8)= 10.2
x = 12.75