HELP ME PLEASE ITS DUE TODAY AT 8

Prove that the sum of two consecutive exponents of the number 5 is divisible by 30.if two consecutive exponents are 5n and 5n + 1, then their sum can be written as 30.

When 142 is added to a number the result is 64 more times the number my options are 35 37 39 41

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.