Using the numbers 2,7,13,11,5 can you get the total of 23? (No negatives, No repetitive Numbers and only)

Chip worked at the animal shelter for 6 hours each week for several weeks. he worked for a total of 42 hours. which of the following can be used to find the number of weeks chip worked at the animal shelter?

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Can anyone me with 32,33,36,37,and 40.