Paul can clean a classroom floor in 3 hours. when his assistant him, the job takes 2 hours. how long would it take the assistant to do it alone?

6 hours

Step-by-step explanation:

If Paul takes 3 hours to clean the floor, then he cleans 13 of the floor per hour. His assistant takes some time t hours to do the same job, so he cleans 1t of the floor each hour. Working together, they clean the floor in 2 hours. This can be written as:

--> 1/3 + 1/t = 1/2

Multiply each side by the least common denominator, 6t.

6t(1/3+1/t)=6t(1/2)

Simplify and solve.

2t+6=3t

2t+6−2t=3t-2t

6=t

answer: do we write it

step-by-step explanation:

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.