Answer:
1
Step-by-step explanation:
x+y=1 if x=0, then y=1
1) This is a combination, so use ⁴⁰C₂.
⁴⁰C₂ = 780
There are 780 handshakes in total.
2) I got my solution by using the combinations formula. Or another way you could do this is to add up... 39 + 38 + 37 + 36 + 35 + 34 + 33 + 32 + 31... +1. You will end up with 780 (I did this to double check my work).
3) The quickest way to figure this out if Drake invited 1,000 people is to use the natural numbers formula = n(n+ 1)/2.
Plug the numbers in: 999(1000)/2 = 499,500
If Drake invited 1,000 people, there would be 499,500 handshakes.
Answer:-2-5÷4-1=-1
Step-by-step explanation:
Answer:
There are 28 dolls, 32 balls, 20 cars for 80 total toys
Step-by-step explanation:
dolls : balls: cars: total
7 8 5 (7+8+5)
7 8 5 20
We have a total of 80
80/20 = 4
We need to multiply each number by 4
dolls : balls: cars: total
7*4 8*4 5*4 20*4
28 32 20 80
There are 28 dolls, 32 balls, 20 cars for 80 total toys
