For this case we have to:

Where:
a: It's the Dividend
b: It is the Divider
c: Is the Quotient
Thus, the expression "the quotient of 5 and x" can be represented as:

Where "y" is the quotient of 5 and x.
ANswer:

The last answer, because the class is being divided into four groups. So the class number is not known, thus it is represented by “w” and divided by four.
KE=0.5xmxv2
=0.5x 1.2x10^3x (3.4x10^3)^2=6936000000
DrH = DrT + 0.019
DrE = DrH - 0.020
DrH is the most and DrE is the least