Can anyone help me with this word problem? Thank you.?

Question

A can of dog food feeds either 3 dogs or 5 puppies. 15 dogs are fed from 12 cans of dog food. The rest is used to feed puppies. How many puppies will be fed?

I know the answer, but I want to understand the logic for future problems.

Thanks a lot you guys. Thanks for the logic as well. Appreciate it.

Answer 1

OK, you have 12 cans of dog food, and you have to feed 15 dogs first and then use the rest to feed puppies. If one can of dog food feeds 3 dogs, and you have to feed 15 dogs, divide 15 by 3 and you get 5 cans of dog food to feed them. With me so far? Good. Now, you started with 12 cans, and 5 of them go to feeding the dogs, so subtract 5 from 12 and you have 7 cans left. So finally, if one can of dog food can feed 5 puppies, multiply 7 by 5 and you end up with 35 happily fed puppies.

Answer 2

Puppies are fed from the leftover dog food.
First, figure out how many cans it takes to feed 15 Dogs:
(15/3 = 5)
Then, subtract that number from the number of cans you have: (12-5 = 7).
You can feed 5 puppies with 1 can of dog food.
Multiply the number of cans you have left by the number of puppies you can feed with 1 can:
(7 x 5 = 35).
You can feed 35 puppies.

Answer 3

you need 5 cans to feed 15 dogs ( 3 dogs per can). You have 7 cans left you can feed 35 puppies with the other cans. ( 5 puppies per can). Hope that helps

Answer 4

I'm assuming that they are only fed one time. But I'm thinking that it would only take 5 cans to feed the 15 dogs (3x5=15) which leaves 7 cans left. 5x7=35 so the answer is 35 puppies. AM I RIGHT!?!?!

Answer 5

6

Answer 6

35

Answer 7

1 can (C) = 3 dogs (D) = 5 puppies (P) ~or~

1C = 3D = 5P ------> 1D = C/3 & P = C/5

15D + XP = 12C (15 dogs + X puppies = 12 cans of food)

15(C/3) + X(C/5) = 12C (substitute D & P in C terms)

5C + XC/5 = 12C

XC/5 = 12C - 5C

XC/5 = 7C

XC = 7C * 5 -------> XC = 35C -------------> X = 35C/C (C cancels out)

X = 35 (where x is puppies)