11. Multiply 6 by 2. Answer is 6. Because when you multiply 8 by 2 you get 16.
12. Divide 24 by 4. You get 6. Now divide 42 by 6. The answer is 7.
P.S sorry if I'm wrong but I think I'm correct.
The books are $5, and the magazines are $10. I’m not sure which way you want it explained but since magazines are twice the price of books, you can solve the equation 3b + 2b = 25. This gives you b=5 which you just multiply by 2 giving you the price of a magazine.
