10 hours
840/168=5
5•2=10 (total number of hours)

The Correct option is ~ B


Let's find the slope (m) using points (2 , 1) and (0 , -3)
hence, slope = 2
now, by Observing the given graph we can infer that the given line cuts the y - axis at point (0 , -3), so value of y - intercept (c) = - 3
[ y - coordinate of a point when x - coordinate is equal to 0 is the value of y - intercept of a line ]
And, we know the general equation of line in slope - intercept form is ~
now, let's plug the value of slope (m) and y - intercept (c) in the general equation to find the equation of line in slope intercept form ~
22.4 × 10.2 ÷2 = 220.8÷2=110.4
500- 300 = 200
750 - 725 = 25
200÷ 25 = 8
it will take them 8 months for the total rent to cost the same