Respuesta :

Your answer is 8 because :

24 = 2 * 12 = 2 * 2 * 6 = 2 * 2 * 2 * 3
40 = 2 * 20 = 2 * 2 * 10 = 2 * 2 * 2 * 5
56 = 2 * 28 = 2 * 2 * 14 = 2 * 2 * 2 * 7

The common prime factor in all is 2 three times so 2 * 2 * 2 = 8.

Hope this helps :)