There are $15$ gymnasts in the Olympic women's competition, including $4$ Americans. The gold medal goes to first place, silver to second, and bronze to third. In how many ways can the medals be awarded to three of the $15$ gymnasts, if exactly one of the Americans wins a medal?

There are 220 ways by which the medals can be awarded to three of the 15 gymnast, if exactly one of the Americans wins a medal

Step-by-step explanation:

From the question, we have;

The number of gymnast in the Olympic women's competition = 15

The number of the gymnast who are Americans = 4

The number of medals awarded = 3 medals

The number of ways hat the medals can be awarded to the three of the gymnast if exactly one of the Americans wins a medal is given as follows;

The number of ways one of the medals can be won by one of the four Americans = ₄C₁ = 4 ways

The number of ways the other two medals can be won by the remaining 11 gymnast = ₁₁C₂ = 55 ways

Therefore, the total number of ways, 'N', the medals can be awarded to three of the 15 gymnast, if exactly one of the Americans wins a medal is given as follows;

N = ₄C₁ × ₁₁C₂

∴ N = 4 × 55 = 220

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have