Answer:
2d+3 dollars
Step-by-step explanation:
the second one 2d+3
Let our basis be worth 1 dollar. A nickel's worth is $0.05. In order to come up with $1, the number of nickels should be:
Number of nickels = $1 * 1 nickel/$0.05 = 20 nickels
Thickness of 20 nickels = 20 nickels * 1.95 mm = 39 mm
Let's do the same for the quarters. Each quarter is worth $0.25.
Number of quarters = $1 * 1 quarter/$0.25 = 4 quarters
Thickness of 4 quarters = 4 quarters * 1.75 mm = 7 mm
Find the ratio of the two:
39 mm/7 mm = 5.57
Therefore, a stack of nickels is 5.57 times thicker than a stack of quarters worth one dollar.
This is the number of combinations of 2 from 23
23C2 = 23! / 2! 21!
A quick way to do this is 23*22 / 2 = 253
It is the same distance from the point A to CD
