Sample Question #258 (brainteaser)

Find a six-digit integer in which the 1st digit is one more than the 3rd digit, the 2nd digit is one less than the 4th, the 5th digit is one less than the 3rd, and the 6th digit is one more than the 4th, and where the sum of the 2nd and 3rd digits equals the 1st digit and the sum of all the digits is 30.

[Source: adapted from the

*Mensa Puzzle Calendar 2008*](Comment: this kind of deductive question is very popular at finance interviews)

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ANSWER

It’s really easy once you write down the question in symbols. Let ABCDEF be the number. The conditions basically give you a system of equations — six equations with six unknowns in this case — which can be solved easily.

The answer is 918273.

BTW, Mensa is an international "society for bright people" … with "a high IQ." Any visitor to my blog a Mensa member?

BDF are consecutive numbers and ECA are consecutive numbers. Hence B + A = D + C = F + E = 30/3 = 10A = C + 1==> then B = 1, and I can come up with the answer 918273.