Three guys go to the bar and get £30 worth of drinks. They pay £10 (10*3=30) each and the waitress takes the money. Before she puts it in the till the manager notices the guys and tells her “I know these guys, give them a £5 discount”
On the way to their table the waitress decides to give the guys £3 back and keep £2 as a tip.
The guys take a pound each, so instead of paying £10 each they end up paying £9 each (9*3=27).
And the question is: if they ended up paying £27 and the waitress kept £2 where did the last pound go?
In: 397
>if they ended up paying £27 and the waitress kept £2 where did the last pound go?
The question itself is a lie. It implies that they payed £27, and the waitress kept a further £2. But the £2 kept by the waitress is part of that £27.
>Three guys […] pay £10 (10*3=30) each […] the waitress […] give the guys £3 back and keep £2 as a tip
You’ve got it right here in the question.
It’s not a math riddle. The waitress took her $2 from her manager, not from the customers.
The issue is with the waitress’ ethics, not the math.
is this supposed to be difficult? 25 went to the bar and 2 to the waitress as ‘tip’.
is this a trick question that I’m too smart to understand?
Lets do this step by step:
Step | Guys | Waitress | Bar
—|—|—-|—-
Start | 30 | 0 | 0
Guys pay | 0 | 0 | 30
Bar gives discount | 5 | 0 | 25
Waitress takes tip | 3 | 2 | 25
No money has actually gone missing.
The tip the waitress took is part of the 27 pounds they paid. At the end, the guys have 3, the waitress has 2, and the bar has 25. So, 3+2+25=30
If I read the story and think of where the money is, it might make more sense too. (G)uys, (W)aitress, (B)ar.
Three guys go to a bar w/ 30 pounds: G = 30, W = 0, B = 0
They pay the waitress 30: G = 0, W = 30, B = 0
The manager says to give back a discount of 5: G = 0, W = 5, B = 25
She gives 3 and takes 2 out of the discount: G = 3, W = 2, B = 25
They paid the bar and tipped the waitress a total of 27 and kept 3 at the end.
The math problem is trying to convince you that you can add the money spent to the money received and get a valid answer. It’s also deceptively leaving out the 25 in the till to confuse you. It’s trying to convince you to add a debt and a credit together both as positive values.
27+2 doesn’t make sense because 27+2+25=60 (we just generated infinite money if we repeat the transaction multiple times)
The math is 27 – 2 =25
Or 27 – 2 – 25 =0 (all dollars are accounted for)
Or 27 debt | 2 credit, 25 credit
The bar manager gave them a £5 discount, so he only expects £25. But they actually paid £27, because the waitress took an extra £2
And you guys gripe about Americans not using metric?
Oh my…. Thank you kind souls of Reddit! I just finished work and I am met with all this…
I never expected this little riddle to get this much attention and now after reading some of your responses I realised that the question really is asked in a way that forces you in a way of thinking that is definitely NOT mathematically correct. That’s what makes it a riddle I guess.
Thank you for all the feedback and thorough explanations a-a-and feel free to mess with your friends using this “riddle” 😉
Latest Answers