Final answer:
The concept of the 'greatest common multiple' is somewhat misunderstood, but it seems the question aims to find the least common multiple of 8 and 10, which is 40.
"the correct option is approximately option D"
Step-by-step explanation:
The question asked is about finding the greatest common multiple of 8 and 10, however, the concept is somewhat incorrect because what is usually sought is the least common multiple (LCM) or the greatest common divisor (GCD) of two numbers, not their greatest common multiple. Nevertheless, if the intent is to determine the least common multiple (which is the smallest number divisible by both numbers), we can find it for 8 and 10.
In this case, the LCM of 8 and 10 is 40. To find it, we can list the multiples of each number, and the smallest multiple they have in common is the LCM. For 8, the multiples are 8, 16, 24, 32, 40, 48, and so on. For 10, the multiples are 10, 20, 30, 40, 50, and so on. The smallest common multiple is 40.
Therefore, the correct answer is: d. 40