He sum of twice a number and 15”

The first five terms of a linear sequence are given below. 7 , 12 , 17, 22 , 27 , what is the next term of the sequence?

When you have 25 numbers, and jake picks 3 random numbers and puts them back, what is the chance bob has of picking those 3 numbers when he picks 6 random numbers (without putting them back)? explain.

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible