There are seven empty seats in a theater, and four customers need to find places to sit. how many different ways can these four seat themselves g

840

Step-by-step explanation:

Given : The total number of empty seats in the theater = 7

The number of customers need to find places to sit = 4

Since here order of their sitting matters , then we use permutation to find the number of ways of sitting.

The number of permutations of n things taking r at a time is given by :-

Then , the number of permutations of 7 things taking  at a time is given by :-

Hence, the number of different ways can these four seat themselves = 840

28

step-by-step explanation:

8+8+6+6

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40