Answer: 360 miles per hour…………………
Let n be unknown number, then 1/5 of this number is 1/5n. When you add these two numbers, you get

You know that this sum is equal to 24, so

1. Multiply this equation by 5:

2. Solve it:

Answer: n=20, correct choice is B.
Answer:
The constant of proportionality is option D i.e 5.
Step-by-step explanation:
Variation:
Variation problems involve fairly simple relationships or formulas, involving one variable being equal to one term. There are two types of variation i.e.
- Direct variation
- Inverse variation
Direct Variation:
Mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other.
Example 
where, k is constant of proportionality.
The above given example is of Direct Variation
∴ y = 5 x
∴ k = 5 = constant of proportionality.
Inverse Variation:
Mathematical relationship between two variables which can be expressed by an equation in which the product of two variables is equal to a constant.
Example 
where, k is constant of proportionality.
Answer:
$125
Step-by-step explanation:
With a 20% off coupon, the price you pay is 80% of the marked price. If that amount is $100, you have ...
$100 = 0.80p
p = $100/0.80 = $125
The maximum price of the shoes you can buy is $125.
_____
<em>Check</em>
20% of $125 is -.20×$125 = $25. When that is subtracted, the price you pay is ...
$125 -25 = $100