In an experiment, the temperature of a liquid at 16.9 degrees Celsius is decreasing at a rate of 2.3 degrees Celsius per minute and the temperature of a solid at 30.7 degrees Celsius is decreasing at a rate
of 6.9 degrees Celsius per minute.

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)