A math test has a total number of 120 points with 44 questions on the test. Questions are worth one, three, or five points. The number of three-point questions is ten less than twice the number of one-point questions so how many five-point questions are on the test?

9 5pt questions

Step-by-step explanation:X+Y+Z=44

1X+3Y+5Z= 120

Y=2X-10

X+3(2X-10)+5Z= 120 X+6X+5Z= 120. 7X+5Z= 120. Multiply top row by -3

X+2X-10+Z=44. 3X-10=44. 3X+Z= 54. Multiply bottom row by 7

-21X-15Z= -450

21X+7Z=378

-8z= -72

Divide by -8

z=9

15 one pt questions+ 20 3 pt + 9 5 pt = 120 pts

15+20+9=44 questions

answer: ratio of volume of cone (with 3 times the height and equal diameter) to volume of cylinder is 2 to 1. the value of π is not used.

step-by-step explanation:

radius is diameter/2 = 4.

area of circle is π r^2.

volume of cylinder is height × area of base = hπr^2 = 3(4^2) π = 48π cubic inches.

not knowing the formula for volume of cone, i calculate it using calculus (which is for calculating things).

volume of cone is integral 0 to h area(y) dy. area(y) is π r(y)^2. r(y) runs r to zero as y runs zero to h, r(0) = r, r(h) = 0.

r(y) = r - r/h y

area(y) = π (r - r/h y)^2 = π (r^2 - 2r^2y/h + r^2y^2/h^2) = π r^2(1-2y/h+y^2/h^2)

antiderivative area(y) = π r^2 (y-y^2/h+y^3/(3h^2))

integral 0 to h = π r^2(h-h^2/h+h^3/(3h^2) - (0)) = π r^2(h - h + h/3) = π r^2(h/3) = π/3 r^2 h

volume of this cone is π/3(4^2)18 cubic inches.

= 6 16 π = 96π cubic inches.

cone has twice the volume, 96/48.

cone height is 6 times the cylinder.

ratio of volume formula: π r^2 cancels.

cone over cylinder ratio is 6h/3 to h, 2 to 1.