Find the five-digit number that has the following pattern: If you put a 1 after it, the number is three times as large as it would be if you had put a 1 before it.

Answer 1

42857 with a 1 after it is 428571 which is 3 times as large as putting a 1 before it, 142857.

3 times 142857 = 428571

Work from the right to the left. The last digit times 3 has to end in a number with 1. That

means an odd number, 1, 3, 5, 7 or 9. Only 3x7= a number ending in 1. The last digit

of the five digit number has to be 7. Continue the process to get all 5 digits and you get

42857.