The least number plus the 207 must be divisible by 17 You have to find the least number which is greater than 207 and is divisible by 17 Thus simply write down the multiples of 17 and select the first number greater than 207 Then find out what number when added to 207, will give the least multiple of 17 greater than 207 Multiples of 17 : 17,34,51,68,85,102,119,136,153,170,187,204,221,238,... The least number greater than 207 is 221 Least number to add =221−207=14