If a variable does not have an exponent, what is understood?

Ivan and jeff buy a package of 8 pens for $4.00. ivan wants 5 of the pens, and jeff wants 3.how much should each student pay?

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?

The manager at gabriela's furniture store is trying to figure out how much to charge for a book shelf that just arrived. the book shelf was bought at a wholesale price of $ 1 4 7 . 0 0 $147.00, and gabriela's furniture store marks up all furniture by 6 0 % 60%. at what price should the manager sell the book shelf?