Respuesta :
Answer:
5
Step-by-step explanation:
factors of 15: 1, 3, 5, 15
factors of 40: 1, 2, 4, 5, 8, 10, 40
factors of 20: 1, 2, 4, 5, 10, 20
hope this helped:)
The answerr is 5 cuz 40 divided by 5 is 8 and 15 divided by 5 is 3 and 20 divided by 5 is 4