Take 15 and divide it by 3 and you get 5. That's what you'll multiply 0.65 by. Divide 56 by 7 and you'll get 8. That's what you'll divide 1.25 by. 5 multiplied by 0.65 is 3.25. 8 multiplied by 1.25 is 10. Add 3.25 and 10 and you'll get 13.25.
The answer is $13.25.