Answer:
(a)
,
,
,
,
,
,
.
(b)
,
,
,
,
,
,
,
.
Step-by-step explanation:
In this exercise we only need to recall the formula for C(n,k):

where the symbol
is the factorial and means
.
By convention 0!=1. The most important property of the factorial is
, for example 3!=1*2*3=6.
(a) The explanations to the solutions is just the calculations.
.
(b) The explanations to the solutions is just the calculations.
For all the calculations just recall that 4! =24 and 5!=120.
Answer:
im am in grade 6
Step-by-step explanation:
sorry......... i apologize.
On day no 9, because to increase her mileage by 4 to reach 8 it will take her 4/0.5=8 days plus day 1 where she ran just 4 miles.
In math, "of" almost always means "times".
So your question is: 3/7 times (the number) = 9
Multiply each side of that equation by 7 : 3 times (the number) = 63
Divide each side by 3 : <em> The number = 21</em>