Answer: first is 4 second is 5
Step-by-step explanation:
This is a combination problem. Order does not matter and the books are all different. You would write this as 21C5 or
. Combinations are not fractions.
The answer is 
which = 20349 different ways these books can be chosen.
Answer:
D. For every 7 dogs, there are 3 cats.
Step-by-step explanation:
Given:
The cost of adults ticket = $18
The cost of children's ticket = $8.25
Total tickets = 2300
Total revenue = $30,168.
To find:
The number of children and number of adults attended the zoo that day.
Solution:
Let x be the number of children and y be the number of adults.
Equation for tickets:
...(i)
Equation for revenue:
...(ii)
Plot the graphs of the given equations on a coordinate plane as shown below.
From the graph it is clear that the graph of both equations intersect each other at (1148,1152).
It means the number of adults is 1148 and the number of children is 1152.
It can be solved algebraically as shown below:
Substitute the value of y in (ii) from (i).




Divide both sides by 9.75.


Putting
in (i), we get



Therefore, the number of adults is 1148 and the number of children is 1152.