Where did the other pound go?

[RJUKL]

Three students spend £30 (£10 each) on pizza. When the pizza boy returns to the restaurant, his boss points out they should only have paid £25 between them. He takes £5 back, but helps himself to £2 and gives the students back £1 each. The students have now paid £9 each making a total of £27. If the boy has kept £2, where did the extra pound go because £27 + £2 = £29

[Eve]

it never went anywhere.

[Mamyalynne]

Shop gets £25
Boy get £2
Students get £3

Total = £30

[ELVIS68]

Garlic Bread?

[snags]

Students... £30... on Pizza... yeah right!

[ELVIS68]

lol@ snags

[Mamyalynne]

Exactly could feed a family of four for a week on that!!

[RJUKL]

Yes, Mamyalynne but each student had handed over a ten pound note to the pizza lad (£30) and when they were handed back £1 each they had each coughed up £9 which makes £27 plus the £2 tip equals £29. Am I as thick as I well? The restaurant only got £25 so I am still puzzled.

[dr b]

the three students each paid 9, total of 27, of which 25 went to the restaurant and 2 went to the pizza boy. 27=27.

[dr b]

neither 30 or 29 are relevant to the explanation.

[Mamyalynne]

You have to work backwards with these types of puzzles.

[RJUKL]

Thanks dr b. Mr brother (a dr G) once explained this to me but I still found it puzzling.

[Mamyalynne]

Yes I am cr@p at puzzles sorry

[mike11111]

The fallacy here is that the students did not pay £9 each for the pizza. They paid £8.33 each to the nearest penny, with the delivery boy pocketing the extra due to them. 3 x £8.33 + £3 change + £2 kept by the boy = £29.99. When I first came across this puzzle in the early 60's, prior to the decimalisation of our currency, the solution was much neater, in that each student paid £8 - 6s - 4d which when multiplied by three and adding the £2 and £3 comes to exactly £30. By the way, at the time I first heard it they were not students but rich businessmen having the full works at a posh restaurant. This was a time when £8 per week was a very good wage for a well-educated school-leaver.

Ah! Nostalgia isn't what it used to be!

[mike11111]

Erratum: In my previous reply I should have given the pre-decimal price as £8 - 6s - 8d rather than 4d, otherwise that would leave me a shilling short and the risk of incurring the wrath of my maths teacher.

[cherrychapstick]

the students paid £9 = £27
£25 for the pizza £2 that the guy took =£27
each student got £1 back = £3 = £30

[Everhelpful]

This is older than me and I am nearly 70!!

[RJUKL]

This is for Mike 11111. I am afraid your answer is incorrect. Each student paid £9 (after they had receiived a refund of £1 each).The tip kept by the delivery boy was £2, the restaurant £25, totalling £29 in all. The figure of £30 was misleading.

[mike11111]

I regret to have to disagree. The £30 cannot be misleading as it was the amount handed over in the first place. The fallacy is that each paid £9 for the pizza, which they didn't. The £9 each covers the cost of the pizzas + the £2 taken by the delivery boy, which together with the £3 refund comes to exactly £30. Quod erat demonstrandum!

[RJUKL]

I still disagree. The three students paid only £9 each for the pizzas (from out of which came the £2 tip). The amount of £30 is misleading since what they spent did not amount to £30 (although they had thought it would).If thatwere the case there would have been no £2 tip.