Answer:
What's the question?
Step-by-step explanation:
,....
Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So

1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
10 to the second power=100
74.75/100= .7475
The answer must be a whole number because for example how are you suppose to fit half a child on a bus that can hold 44 people when it already holds that amount.
It will always be a whole number because if there are several left over students they will be put in another bus with more empty seats.
D : c = 33 : 22
where d is the number of dogs and c is the number of cats;
and: d + c = 3030
33 c = 22 d / : 11
3 c = 2 d
From the other equation: c = 3030 - d
3 * ( 3030 - d ) = 2 d
9090 - 3 d = 2 d
5 d = 9090
d = 9090 : 5
d = 1818
Answer: There are 1818 dogs in the shelter.