Answer:
A =63.585 in^2
Step-by-step explanation:
The area of a circle is found by
A = pi r^2
A = pi (4.5)^2
A = pi(20.25)
We can approximate pi by 3.14
A = (3.14) (20.25)
A =63.585 in^2
Thank you for posting your question here. Please see below answers for the problem above:
a. to find the circumference of the tire you need to multiply 3.14 by 2.5:
= 3.14 x 2.5
= 7.85 to round of it will be 8
b. to get the number of times the tire have to rotate to travel 1 mile:
1 mile = 5,280 ft
1 rotation is 7.85
5,280/7.85 = 672.611465
Answer:
f(t) = 5×0.87^t
Step-by-step explanation:
The general form for an exponential function described in this fashion is ...
... f(t) = (starting value) × (1 + (percent change))^t
Here, the "percent change" is -13%, or -0.13.
Then the value (1 + percent change) is (1 + (-0.13)) = 0.87. Putting this and the starting value into the form above, we have ...
... f(t) = 5 × 0.87^t
Let x represent the amount to be added. The total amount of tin will be
15%·20 + 10%·x = 12%·(20+x)
(15%-12%)·20 = (12%-10%)·x
3%·20/2% = x
30 = x
30 pounds of 10% tin must be added to get a 12% mixture.
