In percent problems, the term rate refers to the

In percentage problems, the term rate refers to the actual percentage itself. Let's look at an example. If you have a principal amount of 1000 and you will be getting a yearly interest of 5%, then the rate is the 5%. We refer to it as the interest rate. So if you are looking for the rate in any percentage problem, then you just have to look for the number that has the percentage symbol. The one with the percentage symbol is always the rate. 

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)