[1] In the natural numbers from 1 to 100, how many times does digit '3' show up?

[3] The product of two whole numbers is 54 and their quotient is 6. What is the larger number?

[5] A box of pencils can be divided equally among 4, 5, 6 or 7 children with no pencils left. What is the smallest number of pencils that the box could have?

[7] Ed's father and mother married 5 years ago. The sum of their ages was 75 when they married . This year, the age sum of Ed and his parents is 88 years old. How old is Ed this year?

[9] 4 students were working on a project as a group at the same rate. They finished

7

8

  of the project in 7 hours. On the following day, only one student can continue to work on it. How many hours will be needed for him to finish the remaining project at the same rate as before?