Notice y° and y° and 50°, are all three angles in a flat-line, namely "linear angles", and since a flat-line is always 180°.
I think it’s 12, if you take $360 and subtract the $120 deposit you get 240 and i divided that by 20 to get 12.

The required number is :
Solution is in attachment ~
Answer:
x <40
Step-by-step explanation:
The income from the pens is 2*x
He made less than 80
2x <80
Divide each side by 2
2x/2 < 80/2
x < 40