# Check my math? **URL:** \ **Category:** Factual Questions\ **Created:** [September 29, 2023, 2:19am UTC](https://boards.straightdope.com/t/check-my-math/990840 "2023-09-29T02:19:40Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [September 29, 2023, 2:19am UTC](https://boards.straightdope.com/t/check-my-math/990840/1 "2023-09-29T02:19:40Z")
I’m watching _Tugboat Annie_. A character has a homework problem: If a fish weighs 10 pounds, and its body weighs twice as much as its head, and its head weighs wtice as much as its tail, how much would its tail weigh? Assigning T as the weight of the tail, I come up with this: 10 = T + 2T + 2 (2T) 10 = T + 2T +4T 10 = 7T T ≈ 1.43 pounds That is, The weight of the tail plus twice the weight of the tail (weight of the head) plus twice the weight of the head (four times the weight of the tail) equals 10 pounds. Am I doing this right? (It’s been a while…) ---
**Author:** ![Xocomil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xocomil/32/14927_2.png) [@Xocomil](https://boards.straightdope.com/u/Xocomil)\ **Post date:** [September 29, 2023, 2:35am UTC](https://boards.straightdope.com/t/check-my-math/990840/2 "2023-09-29T02:35:02Z")
I worked it out the same way. Looks right to me. ---
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [September 29, 2023, 2:38am UTC](https://boards.straightdope.com/t/check-my-math/990840/3 "2023-09-29T02:38:14Z")
Looks right to me. The way the problem is phrased is that the entire weight of the fish is 7 times the weight of its tail alone, as you put it. The fish consists of: Head = 2 tails Body = 4 tails Tail itself = 1 tail So the fish adds up to 7 tails. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [September 29, 2023, 2:42am UTC](https://boards.straightdope.com/t/check-my-math/990840/4 "2023-09-29T02:42:40Z")
> [@Xocomil](#): > > Looks right to me. > [@Velocity](#): > > Looks right to me. Thanks. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [September 29, 2023, 2:56am UTC](https://boards.straightdope.com/t/check-my-math/990840/5 "2023-09-29T02:56:22Z")
That’s correct if you make the rather weird assumption that the fish’s head, tail and body are three disjoint parts of the fish. Using more normal terminology, where the head and tail are part of the body, the tail weighs 2.5 pounds, the head weighs 5 pounds, and the whole body weighs 10 pounds. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [September 29, 2023, 3:15am UTC](https://boards.straightdope.com/t/check-my-math/990840/6 "2023-09-29T03:15:47Z")
> [@markn\_1](#): > > That’s correct if you make the rather weird assumption that the fish’s head, tail and body are three disjoint parts of the fish. I didn’t write the script. 😉 I assume the question, which is unanswered in the film, was meant to sound complicated. Since the head, ‘body’ and tail are separated in the question, I took the values as given. ---
**Author:** ![Xocomil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xocomil/32/14927_2.png) [@Xocomil](https://boards.straightdope.com/u/Xocomil)\ **Post date:** [September 29, 2023, 3:17am UTC](https://boards.straightdope.com/t/check-my-math/990840/7 "2023-09-29T03:17:24Z")
Yeah, it depends what part of the fish is part of the body. If the head and tail are part of the body then the tail weighs 2.5 lbs. If the head is distinct from the body then the tail weighs ~1.67 lbs. If the head and tail are distinct from the body then the math in the op holds. ---
**Author:** ![Moonrise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/moonrise/32/14764_2.png) [@Moonrise](https://boards.straightdope.com/u/Moonrise)\ **Post date:** [September 29, 2023, 11:48am UTC](https://boards.straightdope.com/t/check-my-math/990840/8 "2023-09-29T11:48:15Z")
> [@Xocomil](#): > > If the head is distinct from the body then the tail weighs ~1.67 lbs. That’s how I read it, and 1.67 is the result I got. ---
**Author:** ![Spiff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiff/32/9852_2.png) [@Spiff](https://boards.straightdope.com/u/Spiff)\ **Post date:** [September 29, 2023, 1:09pm UTC](https://boards.straightdope.com/t/check-my-math/990840/9 "2023-09-29T13:09:48Z")
No, I will not check your math. ---
**Author:** ![Limmin](https://avatars.discourse-cdn.com/v4/letter/l/f04885/32.png) [@Limmin](https://boards.straightdope.com/u/Limmin)\ **Post date:** [September 29, 2023, 1:11pm UTC](https://boards.straightdope.com/t/check-my-math/990840/10 "2023-09-29T13:11:41Z")
Yes, 1/7 of 10 lbs is how I read it. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [September 29, 2023, 5:36pm UTC](https://boards.straightdope.com/t/check-my-math/990840/11 "2023-09-29T17:36:29Z")
The question is totally ambiguous. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [September 29, 2023, 5:39pm UTC](https://boards.straightdope.com/t/check-my-math/990840/12 "2023-09-29T17:39:12Z")
As opposed to partially ambiguous?