puzzletarget-25
Make 25 from 8, 3, 6 and 1
Use 8, 3, 6 and 1 once each. You may add, subtract, multiply, divide, and use brackets. Make the expression equal 25. This is a puzzle on the page. It is the example behind Target 25, and it is not a live round.
The constraint
Each of the four numbers has to appear once. You cannot bring in a 5 from outside, even though 5 × 5 is a tempting picture of 25. If a 5 appears, it has to be built from the numbers you were given.
The operations allowed in a future Target 25 round are not fixed yet. For this puzzle, ordinary arithmetic and brackets are enough.
What to try first
25 is 5 × 5. That suggests looking for two ways to make 5 from what you have. It is also 18 + 7, or 26 − 1, if those pieces are easier to build from 6, 3, 8 and 1.
Try it
medium
Make 25. Use 8, 3, 6 and 1 once each, with ordinary arithmetic and brackets.
A way through
- Factor the target before you combine at random.
- Check that every given number appears once before you accept an expression.
Related
- Target 25
The planned game this example belongs to.
- More target-style puzzles
- The Numbers arena
Numbers rounds are in development. Joining the list does not open a game.