To find the probability of not picking an 8, we need to calculate the number of favorable outcomes (not picking an 8) divided by the total number of possible outcomes (picking any card).
In this case, there are 3 favorable outcomes (picking a 5, 6, or 7) out of a total of 4 possible outcomes (the given cards). Therefore, the probability of not picking an 8 is 3 out of 4, which can be expressed as 75%.