The linear equation of relating two objects can be written in the form,
y = ax + b
Our x is the number of passenger and y is the weight (in tons). Using the first two conditions,
10 = 60(a) + b
13 = 84(a) + b
The values of a and b from the equations are 0.125 and 2.5.
For 50-passenger bus,
y = (50)(0.125) + 2.5
The value of y is 8.75.
