Find the arithmetic mean of three numbers, if the first of the tries is 80

Find the arithmetic mean of three numbers, if the first of the tries is 80, the second is 1.5 times the first, and the third is 20% of the sum of the first and second.

1) Find the second number. If … times more, then you need to multiply.

80 * 1.5 = 120.

2) Find the sum of the first two numbers.

80 + 120 = 200.

3) Find the third number. To find the percentage of a number, you need to convert the percentage to a decimal fraction, and multiply the given number by this fraction. 20% = 0.2.

200 * 0.2 = 40.

4) Find the arithmetic mean of three numbers 80, 120 and 40. To find the arithmetic mean, add these numbers and divide by their number, by 3.

(80 + 120 + 40) / 3 = 360/3 = 120.

Answer. 120.