The midpoint of a line segment partitions the line segment into a ratio of

1: 1.
1: 2.
2: 1.
2: 3.

The midpoint of a line segment partitions the line segment into a ratio of 1:1

Step-by-step explanation:

Given: Consider line AB with x cm length with mid point O on it.

Proof:

AO=BO=(mid point divides the line into equal halves)

The ratio of the in which mid point divided the line segment: AO:BO==1:1

So,the midpoint of a line segment partitions the line segment into a ratio of 1:1.

the answer to this question is "motor unit"

probability for j is 1/4

while

a is 1/6