Ok so I'm reading a book right now that tackles pre-algebra and I stumbled on this example problem that goes like this.
Jerry bought a pie and ate 1⁄5 of it. Then his wife Doreen ate 1⁄6 of what was left. How much of the total pie was left?
The authors solution is to solve it like this.
First, subtract 1/5 from 1/1 (pie) which equals 4/5, and then multiply 1/6 to 4/5 to get how much Doreen ate from the whole pie, 4/30.
My way obviously is to solve it like this.
First subtract 1/1 by 1/5 (the same with the author), but then I subtract 4/5 with 1/6, which gives me a totally different answer, 19/30.
So my questions are these,
1.) Why does subtracting one fraction to another not work in this scenario. (Because I have a different result)
2.) Obviously (for me) I should subtract based on the question, but why does the author use multiplication instead?
3.) And why does multiplying instead of subtraction work?