Answer:
500 phones
Step-by-step explanation:
cost of manufacturing: y = 80x + 10,000
money from phone sales: y = 100x
* note: x = #phones
solve for when they're equal;
100x = 80x + 10,000
100x - 80x = 80x - 80x + 10,000
20x = 10,000 –––––––––––> divide both sides by 20
x = 500
35
the ratio for the two is 5:7 and you want to find _:49. to get from 7 to 49 you multiply the 7 by 7. because you did that to one side you have to do the same to the other and multiply 5 by 7 which gives you 35
Step One
Calculate the number of feet traveled in 1 rotation.
Formula
C = π*d
P = 3.14
d = 9 inches = 9/12 feet = 3/4 of a foot.
C = 3.14 * 3/4 = 2.355 So that means that every time the tire turns around 1 complete turn, the distance traveled on the ground is 2.355 feet.
Step Two
Figure out the number of revolutions.
1 revolution = 2.355 feet
x revolutions = 300 feet.
1/x = 2.355/ 300 Cross multiply
2.355 feet * x = 1 rev * 300 feet
2.355 x = 300 rev Divide by 2.355
x = 300 / 2.355
x = 127.39 revolutions. <<<< Answer
