# Math Is Fun Forum

Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

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## #1 2022-08-15 07:31:21

Abbey78336
Member
Registered: 2022-08-15
Posts: 37

### Wonderful Base number

A three digit number in base 7 changes to base 9 by reversing their digits what is that number

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## #2 2022-08-15 13:40:32

Jai Ganesh
Registered: 2005-06-28
Posts: 44,437

### Re: Wonderful Base number

Hi,

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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## #3 2022-08-16 00:58:12

Abbey78336
Member
Registered: 2022-08-15
Posts: 37

Thanx ganesh

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## #4 2022-08-16 19:50:29

Bob
Registered: 2010-06-20
Posts: 9,864

### Re: Wonderful Base number

hi Abbey78336 and Ganesh,

I'm getting another solution:

At this line b = 8(3a - 5c) there are two other posible b values to check, namely b =4 and b = 8

The first does not lead to a solution, but b = 8 does.

I'll leave the rest as an exercise.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

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