Answer: 280
<u>Step-by-step explanation:</u>
Quantity X Cost = Money Received
Adult: x 3 3x
Children: 500-x 2 2(500 - x) = 1000 - 2x
Adult = Children + 400
3x = 1000 - 2x + 400
3x = 1400 - 2x
5x = 1400
x = 280
Remark
Many calculators have a key that will do this in one step. Mine is one of them. So let's start with the answer and then we'll do it the long way.
9C3 = 84. You put it into your calculator as 9 2nF nCr 3 =
Solution

3*4*7 = 84 which is what you set out to show.
Answer:
65/80 score
Step-by-step explanation:
Answer:
All natural numbers are whole numbers because in the numbers diagram natural numbers are within whole numbers
Step-by-step explanation:
Answer:
the 4th one
Step-by-step explanation: