Let us always base on the present age. We denote this by x. Now, the age he had 2 years ago would then be denoted as (x-2). Let's equate this to 20 years old.
x - 2 = 20
x = 20 + 2
x = 22 years old
He should be 22 years old now.
Let's check the other condition. After 1 year, his age should be (x+1). Let's equate this to 23 years old.
x + 1 = 23
x = 23 - 1
x = 22
Thus, this is possible if Reuben is 22 years old as of the present.
Basically the answer is 6, if you'd like an explanation, let me know. :)
Answer:
680
Step-by-step explanation:
Use the binomial coefficient where you choose 
numbers out of 
possible numbers and find the total amount of combinations since order does not matter:
Thus, you can make 680 three-non-repeating-number codes
Answer:
it is because 20 + 20 is 40 and then 40 - 20 = 20
You go A to B & B 2A + 8 + B to A&A to B&B to a and then you go see 2D to see 2D to see you today to see 2D which equals a + 8 + 8 + 8 + 8 and that's your answer for this question I know it doesn't look like it makes sense but it's correct I think
