Question

The temperature of magnesium must be at least 650 degrees for the metal to melt. A sample of magnesium is currently 255 degrees. The temperature of the magnesium is increased by 10 degrees every minute. Which inequality shows the number of minutes (m) needed to raise the temperature to the melting point?
A m >39.5
B m greater then equal to 39.5
C m > 87.5
D m greater then or equal to 87.5

Answer 1

The total temperature of the magnesium sample is its original temperature plus the temperature increase which is dependent on time. This total should exceed 650 degrees. Thus, the inequality that best describes the condition is,                
                                        255 + 10m ≥ 650
                                                   m ≥ 39.5
The answer is letter b.