Joe says that the product of a 4 digit number and a 1 digit number is always a 4 digit number does joe's statement makes sense?

No, what Joe said isn't necessarily true. Though it is common that the product will be a 4 digit number, because you can use any number, like a large 4 digit number like 9999 or a large 1 digit number like 9, that isn't true. For instance: "9999 x 9" is 89991 which is 5 digits instead of 4 because "9999" is the biggest 4 digit number and "9" is the biggest "1" digit number.

total amount of money that he should pay if he has not used his duty free exemption is $98

step-by-step explanation:

given a united states citizen returning to the states declares the following items at the customs office: 3 shirts at $8.50 each 2 dresses at $27.50 each 1 pair of gold cuff links at $17.50 per pair. we have to find how much he pay

cost of 3 shirts if one cost at $8.50 is

cost of 2 dresses if one cost at $27.50 is  

cost of 1 pair of gold cuff at $17.50

so, total amount of money that he should pay if he has not used his duty free exemption is   $25.5+$55+$17.50=$98