the answer is 61. i knew it had to be an odd number because 1 was left over when divided by 2. i knew that the last number was 1 because of the 5. then by starting at 20 i went up by 10s to get my answer
or
take 3×4×5 = 60. i dont use the 2 because if divisible by 4 then it is also divisible by 2. then add 1 to get 61.
