（AMC 2020 Question \#26）  Janine thinks of three numbers.  Between them, they use the digits 1, 3, 5, 6, 7, 8 and 9, with each digit being used exactly once.  The second number is 2 times the first number.  The third number is 4 times the first number.  What is the third number? 
Overseas Competition->Knowledge Point->Word Problem Modules->Questions Involving Sum, Difference and Multiples->Questions Involving Varying Multiples