Answer:
3
Step-by-step explanation:
It is 3 because fi you multiply 5 by 3 you get 15, and if you multiply 10 by 3 you get 30. Subtract 30 by 6 and get 24. And finally, if you multiply 2 by 3 it gives you 9. 9+12= 21.
Answer:
The correct answer is (edit: b).
Step-by-step explanation:

4 kilometres is 4000 meters
4000 meters - 3400 meters = 600 meters
and as John is the one that rode 4 kilometres he rode further and by 600 meters
Answer:
N=17
?=15
Explanation;
Check out my attached work
Hope it helps, let me know if you have any questions