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Using the given numbers, make an expression whose value is 639 Question
Using the numbers $3, \ 7, \ 25, \ 50, \ 75, \ 100$ (each used at most once), along with any number of the four basic arithmetic operations (addition, subtraction, multiplication and division) and parentheses, construct an expression whose value is $639.$
You can’t use anything other than what is explicitly allowed. So, for example, you can’t use square roots, concatenation, decimal points, negation, bases other than 10, ...
I know of two solutions. One uses all six given numbers, the other only uses some of the given numbers.
Attribution:
Countdown Game Show
2 answers
The following users marked this post as Works for me:
| User | Comment | Date |
|---|---|---|
| will.octagon.gibson | (no comment) | Aug 4, 2026 at 15:42 |
A solution using fewer than 6 of the numbers
$$\left(75 + \frac{50}{25}\right)\times 7 + 100 = 639$$
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A solution that uses all 6 numbers
$\Large \frac{75}{3} \times 25 \ + \ \frac{100}{50} \times 7 = 639$
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