Two mechanics worked on a car. the first mechanic worked for 10 hours, and the second mechanic worked for 5 hours. together they charged a total of $1500 . what was the rate charged per hour by each mechanic if the sum of the two rates was $195 per hour?

The first mechanic charges $105 per hour, and the second mechanic charges $90 per hour.

Step-by-step explanation:

If x is the rate of the first mechanic, and y is the rate of the second mechanic, then:

10x + 5y = 1500

x + y = 195

Solve the system of equations using elimination or substitution.  Using substitution:

10x + 5 (195 − x) = 1500

10x + 975 − 5x = 1500

5x = 525

x = 105

y = 195 − x

y = 90

The first mechanic charges $105 per hour, and the second mechanic charges $90 per hour.

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.