Problem:
I have written a strictly increasing sequence of six positive integers, such that each number (besides the first) is a multiple of the one before it, and the sum of all six numbers is . What is the largest number in my sequence?
Problem:
I have written a strictly increasing sequence of six positive integers, such that each number (besides the first) is a multiple of the one before it, and the sum of all six numbers is . What is the largest number in my sequence?
Solution:
If the fourth number is , then the last three numbers must sum to at least . This is impossible, so the fourth number must be less than . Then the only way we can have the required divisibilities among the first four numbers is if they are . So the last two numbers now sum to . If we call these numbers () then we get , which forces . So the last two numbers are .