Answer:
1716 ways
Step-by-step explanation:
Given that :
Number of entrants = 13
The number of ways of attaining first, second and third position :
The number of ways of attaining first ; only 1 person can be first ;
Using permutation :
nPr = n! ÷(n-r)!
13P1 = 13! ÷ 12! = 13
Second position :
We have 12 entrants left :
nPr = n! ÷(n-r)!
12P1 = 12! ÷ 11! = 12
Third position :
We have 11 entrants left :
nPr = n! ÷(n-r)!
11P1 = 11! ÷ 10! = 11
Hence, Number of ways = (13 * 12 * 11) = 1716 ways
90/2 is 45.. 60/2 is 30.. 30+45=75... 75 students would be able to be in each of the 2 groups, each containing 45 girls and 30 boys ... Hope I helped (:
Answer:
7 months
Step-by-step explanation:
He plans on depositing $200 every month into the savings account that already has $600 in it.
We can represent the amount of money he will have after a certain number of months (x) as:
A = 600 + 200x
He needs to save $2000. Therefore, to find the months he needs to save, we need to find x when A is $2000:
2000 = 600 + 200x
200x = 2000 - 600
200x = 1400
x = 1400/200 = 7 months
He needs to save for 7 months.
{1,2,3,4,5,6,7,8}= Sample space
