Take away ¯MAD from ¯MADMADAM to make her prime. ¯ADAM is prime too if he does not get mad: ¯MADADAM.
M,A,D are 3 distinct digits that are to be determined by you so that the statements in this puzzle are true.
Answer
So, we have two prime numbers (MADMADAM-MAD, ADAM
).
Consequently, from a more mathematical standpoint,
M∗10,010,001+A∗1,001,010+D∗100,100−(M∗100+A∗10+D) is prime, as is A∗1,010+D∗100+M.
I ran this through a little program that I wrote, and I discovered that there are three distinct solution sets. They are:
M: 1 A: 5 D: 8 --> 15,815,851−158=15,815,693, which is prime. 5851 is also prime.
M: 3 A: 1 D: 6 --> 31,631,613−316=31,631,297, which is prime. 1613 is also prime.
M: 3 A: 5 D: 6 --> 35,635,653−356=35,635,297, which is prime. 5653 is also prime.
If you're interested, here's the Java program that I wrote to find the answer. It probably isn't super efficient, but it works.
public class Test {
public static void main(String[] args) {
int big = 0;
for(int i = 1; i<=9; i++) {
for(int j = 1; j<=9; j++) {
for(int k = 0; k<=9; k++) { //k (or d) is the only digit which could be 0.
if(isPrime(i*10010001 + j* 1001010 + k*100100 - (i*100 + j*10 + k))&&
isPrime(j*1010 + k*100 + i)) {
big = i*10010001 + j* 1001010 + k*100100 - (i*100 + j*10 + k);
System.out.println("M: " + i + " A: " + j + " D: " + k);
System.out.println(""+i+j+k+i+j+k+j+i+"-"+ i+j+k+"="+big+
", which is prime. "+j+k+j+i+" is also prime.\n");
}
}
}
}
}
public static boolean isPrime(int i) {
boolean prime = true;
for(int j = 2; j<=i/2; j++) {
if (i%j==0) {
prime = false;
break;
}
}
return prime;
}
}
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