快猫短视频

#75 Seventh time lucky?

Septa wants to use a cash machine, but she has forgotten the PIN for her bank card. She has made six guesses so far, with no success:

5 7 2 6

7 3 5 8

1 1 9 1

7 6 2 8

4 8 8 2

9 3 0 7

Suddenly, she remembers that her PIN鈥檚 four digits are different. Her bank has a rule of 鈥渟even strikes and you鈥檙e out鈥�, so she has just one more attempt before the machine swallows her card. As it happens, she had one correct digit in the right position in each of her guesses. What is her PIN?

Answer next week

#74 The twisted wood

Solution

I chose Twitton. Since only the first and last letters matter here, shorten each name so that Spotton, for example, becomes SN. Then sort them alphabetically:

FE, FR, HT, ME, SL, SN, TE, TE, TN, TO, WT, WY

I can鈥檛 have told Tweedle a name beginning with H or M, or he would know who I chose. Eliminate those, leaving:

FE, FR, SL, SN, TE, TE, TN, TO, WT, WY

I can鈥檛 have told Twaddle a name ending with R, L, O, T or Y, which leaves:

FE, SN, TE, TE, TN

I can鈥檛 have told Tweedle a name beginning with F or S, so that leaves:

TE, TE, TN

But Twaddle now knows, so it must have been Twitton.