At a certain high school, 25 students play only stringed instruments, 15 students play only brass instruments, and 5 students play both. There are also 5 students who play neither stringed nor brass instruments. What is the probability that a randomly selected student plays both a stringed and brass instrument?

1/10

Step-by-step explanation:

First, let's find the total number of students (25+15+5+5). We don't need to worry about them overlapping, as the questions says "only." We get the total of 50.

Out of the 50 students, there are 5 students that play both instruments. This means that 5 is our numerator and 50 is our denominator, giving us 5/50 or 1/10.

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6