Answer:
- The lamp burns 6 ounces of oil per min.
Explanation:
That the oil of a lamp burns at a linear rate means that the rate of burn is constant.
Hence, you can calcualte the rate with which the lamp burns the oil using any two ordered pairs.
- Rate of burn = [ change in oil ] / [change in time]
- Rate of burn = [Oil at time 2- Oil at time 1 ] / [time 2 - time 1]
Your two ordered pairs are (13 ounces, 10 min) and (7 ounces, 38 min).
Substituting those pairs in the equation for the rate, you get:
- Rate = [ 7 ounces - 13 ounces ] / [38 min - 10 min]
- Rate = ( - 6 ounces) / (18 min) = - 1/3 oz / min ≈ - 0.33 oz / min
The negative sign just shows that the amount of oil is decreasing (the oil is being burned).
Hence, the lamp burns 6 ounces of oil per min.
