Last month a phone company charged $0.07 per minute for the first 300 minutes of calling time and $0.05 per minute for each minute of calling time in excess of the first 300 minutes. for how many minutes of calling time was bob charged by the phone company last month?

The total minutes for last month is 300 + 800 = 1100 minutes.

Step-by-step explanation:

Last month a phone company charged $ 0.07 per minute for the first 300 minutes of calling time and $0.05 per minute for each minute of calling time in excess of the first 300 minutes . For how many minutes of calling time was Bob charged by the phone company last month?1) Last month the phone company charged Bob $21.00 for his calling time that was charged at $0.07 per minute.2) Last month the phone company charged Bob $40.00 for his calling time that was charged at $0.05 per minute.

1) If Bob was charged $0.07 per minute, it means the call was within the first 300 minutes. He was charged $21.00 for last month at $0.07per minute. Therefore, he called for:

He called for 300 minutes with $21.00

2) If Bob was charged $0.05 per minute, it means the call was outside the first 300 minutes. He was charged $40.00 for last month at $0.05 per minute. Therefore, he called for:

He called for additional 800 minutes with $40

Therefore, the total minutes for last month is 300 + 800 = 1100 minutes.

i dont know sorry

step-by-step explanation:

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.