Question

HELP WITH THIS QUESTION ASAP!!!!!!

Suppose P and Q both represent prime numbers such that

5 x P + 7 x Q= 109
Find the value of the prime P.

Answer 1

on rearranging,

`p = (109 - 7q)/(5)`

now, 109-7q should be a multiple of 5,

and for that, 7q must end with 9 or 4 as unit digit.

as q is prime,

let's try q=2,

(109-7×2)/5=95/5=19

which is a prime.

hence, P=19 and Q=2

we got lucky.