The inflation rate of the u. s. dollar is 3.1 percent. what this means is that every year, prices increase by 3.1 percent. if a paperback book costs $1.98 three years ago, what does it cost now?

Due to inflation, the cost of goods at any time t is calculated through the equation, 
                                  F = P x (1 + r)^n
Substituting the values given above,
                                 F = ($1.98) x (1 + 0.031)^3 = 2.1699
Therefore, the paperback book costs approximately $2.17 now. 

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)