Gone fishing: ow many of her fish weighed less than 2 lbs?

[pianoplaya16]

At a fishing tournament you are advanced 1$ for each fish weighing 2 lbs or over and you are fined 2$ for each fish weighing less than 2lbs. Given that, Sue caught 12 fish, but neither made nor lost money. How many of her fish weighed less than 2 lbs?

 

[jonboy]

Just use logic.

For every fish \(\displaystyle \,\ge\,\) 2 pounds, you make a dollar.
For every fish \(\displaystyle \,<\,\) 2 pounds, you subtract 2 dollars.
Sue caught 12 fish and got no profit.

You know you're going to have more \(\displaystyle \,\ge\,\) 2 pound fish since you have to have to gain no profit.

So when you have 6 \(\displaystyle \,\ge\,\) 2 pound fish and the 6 remaining you're gonna have lost 6 dollars. So we need more \(\displaystyle \,\ge\,\) 2pound fish.

So for 7 \(\displaystyle \,\ge\,\) 2 pound fish, we have 5 \(\displaystyle \,<\,\) 2 pound fish and that means we lose 3 dollars.

But when we have 8 \(\displaystyle \,\ge\,\) 2 pound fish and 4 \(\displaystyle \,<\,\)2 pound fish, we have 8$ - 8$ = 0

 

[Mrspi]

Re: Gone fishing

At a fishing tournament you are advanced 1$ for each fish weighing 2 lbs or over and you are fined 2$ for each fish weighing less than 2lbs. Given that, Sue caught 12 fish, but neither made nor lost money. How many of her fish weighed less than 2 lbs?

Let x = number of fish weighing 2 pounds or more

Let y = number of fish weighing less than two pounds

You know Sue caught 12 fish, so

x + y = 12

You also know that Sue didn't make any money or lose any money.

1x + (-2y)= 0

Ok...can you work with that? If you're still having trouble, please repost showing all the work you did.