Henry Ernest Dudeney/Puzzles and Curious Problems/172 - Curious Multiplicand/Solution

by : $172$

 * Curious Multiplicand

Solution

 * $142 \, 857$

Proof
This is, of course, the recurring part of the decimal expansion of the Reciprocal of 7:


 * $\dfrac 1 7 = 0 \cdotp \dot 14285 \dot 7$

Hence:

Also see

 * Properties of 142,857