Answer:
$130
Step-by-step explanation:
This is a direct proportionality between the amount he makes and the time worked. As the time increases, so does the amount he makes and vice versa.
Let the amount made be A and the time T
A ∝ T,
A = KT where K is the constant of proportionality
where Jon makes $78 in 12 hours of work, A = 78, T = 12
78 = 12K
K = 6.5
A = 6.5T
In 20 hours of work, T = 20
A = 6.5 × 20
A = $130
