Question

If a large factory sells its new gadgets for $5 each, it can sell 1050 per month, and if
it sells the same gadgets for $9, it will sell 900 per month. To the nearest whole
number, how many gadgets could be sold per month, if the price was $12?

Answer 1

(5, 1050), (9, 900), (12, y)
For linear relation,
(y-1050)/(12-5) = (900-1050)/(9-5)
Solve for y,
y = 787.5

Round to the nearest whole number which will be 788