Respuesta :

21:30 and 35: and 50 this is because 7 times 3 is 21, 10 times 3 is 30, and 7 times 5 is 35, and lastly 10 times 5 is 50

Answer: 17:20

Step-by-step explanation:

7 is 3 away from 10, 17 is 3 away from 20, hope this helps