Answer: 3000 stamps
Step-by-step explanation:
Given
Chris and Josh have 1800 stamps
Josh and Jessica have 2200 stamps
Jessica and Chris have 2000 stamps
Suppose Chris, Josh, and Jessica have 
stamps
Thus, all three have 3000 stamps
First slot, 11 options
2nd is 10 (1 less than 1st slot)
3rd is 9
4th is 8
11*10*9*8=7920 different pizzas (assuming you can't order all 1 topping)
Answer:
It will take 100 songs for the monthly price of Napster to cost the same as iTunes.
Step-by-step explanation:
Let's create two equations to represent iTunes (T(d)) and Napster (N(d)):
T(d)=0.99d
N(d)=0.89d+10
In order for us to find when the two prices will be the same, let's set the equations equal to each other and solve for x:
0.99d=0.89d+10
0.1d=10
d=100
280 divided by 7 = 40 pages every night
(28/7=4, add a zero)
