Our Red Numbers are 56, 61, 66, ?, and 76. The difference between each of the first three numbers is 5. If we add 5 to 66, we get 71, and the difference between 71 and 76 (the final known number) is also 5. So the Red solution is 71.
Our Red Numbers are 56, 61, 66, ?, and 76. The difference between each of the first three numbers is 5. If we add 5 to 66, we get 71, and the difference between 71 and 76 (the final known number) is also 5. So the Red solution is 71.