PYHIYP means:
Put your hands in your pockets i.e. use no calculators, no pen & paper; just your eyes and you brain.
The 1st task, a harbinger to be followed by many others, is to prove just by observation and common sense that none of the four numbers listed below is a prime.
i. 5,234,567,896,743
ii. 1,438,525,775,258,341
iii. 77,112,356,378,491
iv. 1,431,436,216,211,339
No time limit!
No cheating!
KISS!
Post your conclusions.
(In reply to
Puzzle Solution: (ii) by K Sengupta)
(iii) 77 is divisible by 7
112 is divisible by 7
35 is divisible by 7
63 is divisible by 7
7 is divisible by 7
84 is divisible by 7
91 is divisible by 7
Consequently, the given number is divisible by 7, and therefore NOT a prime number.
(iv) We know that:
1001= 77*13
So, any number divisible by 1001 must be divisible by 13.
Now, 143143=143*1001 --> the number is divisible by 13.
621621= 621*1001 --> the number is divisible by 13
13 is divisible by 13
and, 39 is divisible by 13.
Consequently, the given number is a multiple of 3 and, therefore not a prime number.
Puzzle Solution: (iii) and (iv)
