Try solving this problem:
How to calculate A time and B time? You need to use this equation:
Heating rate = 5 °C/min
Time = A
Temperature = (T2-T1) = (650-30) °C = 620 °C
Based on equation 1:
t = 124 min = 2 hours 4 min = 2.067 hours.
To solve B is same as calculate A.
Try calculate B. The answer for B time is; t = 1.033 hours.