Search results

Re: Australian Mathematics Competition $Any 4 digit palindrome can be expressed in the form:$ $1001x + 110y$ $We wish to determine which of these are divisible by 7$ $Note the following$ 7 | 1001 \implies 7 | 1001x 7 \nmid 110 $Hence if the palindrome is a multiple of 7, then$ 7 | y...