The total amount that Chang will received from his wages is the product of his hourly wage times the number of hours he has worked (n). His total savings should not be less than $125. The equation that best describes the situation is,
45 + 7n ≥ 125
Solving for n in the inequality gives an answer of n≥11.42 hours. Thus, he needs to work for at least 12 hours.
I says every time you INCREASE by 1 degree Farenheit you go up 59 degrees C, so it is false. Same for III, if you go up or down 1 degree C that's not a change of 59 in degrees F.
That leaves B, which is right if you experiment with the math.