Answer:
$19.85 tip
Step-by-step explanation:
To find the % of something simply turn 20% to a decimal (.2) then times it by the number you want .2 * 99.25 = 19.85
First of all calm down and brake down the problem plan a is $25 a month while the other one is $40 you need to subtract to get $15 than divide $15 by $0.25 which you will get 60 but this is not the right answer because its asking you how many phone calls is the cost of plan b less than the cost of plan a so the answer is 59 calls.
If I am not mistaken, you cross multiply then divide.
Let the square base of the container be of side s inches and the height of the container be h inches, then
Surface are of the container, A = s^2 + 4sh
For minimum surface area, dA / ds + dA / dh = 0
i.e. 2s + 4h + 4s = 0
6s + 4h = 0
s = -2/3 h
But, volume of container = 62.5 in cubed
i.e. s^2 x h = 62.5
(-2/3 h)^2 x h = 62.5
4/9 h^2 x h = 62.5
4/9 h^3 = 62.5
h^3 = 62.5 x 9/4 = 140.625
h = cube root of (140.625) = 5.2 inches
s = 2/3 h = 3.47
Therefore, the dimensions of the square base of the container is 3.47 inches and the height is 5.2 inches.
The minimum surface area = s^2 + 4sh = (3.47)^2 + 4(3.47)(5.2) = 12.02 + 72.11 = 84.13 square inches.
Work shown in the picture. There are 1.25 x 10^9 titanium-44 atoms and 1.875 x 10^10 scandium-44 atoms.
