## Interview Questions

 Puzzles
 There is a unique number of which the square and the cube together use all ciphers from 0 up to 9 exactly once. Which number is this? Ans:  The number is 69: 69^2 = 4761 and 69^3 = 328509..
 The gentlemen Dutch, English, Painter, and Writer are all teachers at the same secondary school. Each teacher teaches two different subjects. Furthermore: Three teachers teach Dutch language There is only one math teacher There are two teachers for chemistry Two teachers, Simon and mister English, teach history Peter doesn't teach Dutch language Steven is chemistry teacher Mister Dutch doesn't teach any course that is tought by Karl or mister Painter. What is the full name of each teacher and which two subjects does each one teach? Ans:  Since Peter as only one doesn't teach Dutch language, and mister Dutch doesn't teach any course that is tought by Karl or mister Painter, it follows that Peter and mister Dutch are the same person and that he is at least math teacher. Simon and mister English both teach history, and are also among the three Dutch teachers. Peter Dutch therefore has to teach next to math, also chemistry. , teacher, he cannot be mister English or mister Painter, so he must be mister Writer. Since Karl and mister Painter are two different persons, just like Simon and mister English, the names of the other two teachers are Karl English and Simon Painter. , Summarized: Peter Dutch, math and chemistry Steven Writer, Dutch and chemistry Simon Painter, Dutch and history Karl English, Dutch and history.
 Barbara has boxes in three sizes: large, standard, and small. She puts 11 large boxes on a table. She leaves some of these boxes empty, and in all the other boxes she puts 8 standard boxes. She leaves some of these standard boxes empty, and in all the other standard boxes she puts 8 (empty) small boxes. Now, 102 of all the boxes on the table are empty. How many boxes has Barbara used in total? Ans:  By putting 8 boxes in a box, the total number of empty boxes increases by 8 - 1 = 7. If we call x the number of times that 8 boxes have been put in a box, we know that 11 + 7x = 102. It follows that x=13. In total, 11 + 13 × 8 = 115 boxes have been used.