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Puzzles

One activity that many of our members enjoy is puzzling! You can test yourself for fun with our brainteasers. Our quizzes and conundrums are updated regularly, so do check back on the page for the latest content, and if you get really good at them, why not find out what your IQ is by booking a Mensa Supervised IQ Test?

1/3/25 – Saint David’s Day

Each letter stands for a different digit 1 – 7, inclusive.

The sum of the digits S + A + I + N + T = 20.

The sum of the digits D + A + V + I + D = 20.

If A = 2 and V ≠ 1 then what is the value of D?

Puzzle courtesy of Mensa member Peter Hooton

  • Show Answer

D = 3

As A=2, 2D + V + I = 18  (all numbers 1 – 7).

Create a table of possibilities – options in brackets can occur in any order.

A D V + I (V, I) (NST)
2 1 16 Not possible
2 2 Not possible as A = 2
2 3 12 (5,7) (1,4,6)
2 4 10 (3,7) (1,5,6)
2 5 8 (1,7) (3,4,6)
2 6 6 (1,5) (3,4,7)
2 7 4 (1,3) (4,5,6)

Neither V nor I can take an even value

Consider values for I if SAINT = 20

A SUM (NST) I D
2 11 7 3
2 12 6 I cannot be even
2 13 5 When (N+S+T=13), D=5
2 14 4 I cannot be even
2 15 3 7

We now have TWO options left

A I D (N, S, T) V
2 7 3 (1, 4, 6) 5
2 3 7 (4, 5, 6) 1

But V ≠1, so the solution is from the top row. D=3

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