The square of the nine-digit number 111 111 111 is an n-digit number.what is the value of n ?
Look at the pattern:
12 = 1, a 1 digit number
112 = 121, a 3 digit number
1112 = 12321, a 5 digit number
11112 = 1234321, a 7 digit number
111112 = 123454321, a 9 digit number
1111112 = 12345654321, an 11 digit number
11111112 = 1234567654321, a 13 digit number
111111112 = 123456787654321, a 15 digit number
1111111112 = 12345678987654321, a 17 digit number
It's the last one in the list, so n = 17.
Edwin
