Let P be the point as (x, x).
then PA = root((x-3)^2 + (x-4)^2))
and
PB = root((x-4)^2 + (x-13)^2)
PA + PB => root((x-3)^2 + (x-4)^2)) + root((x-4)^2 + (x-13)^2)
Now to minimize it the whole expression should be equal to zero.
that is (x-3)^2= 0 and (x-4)^2 = 0 and (x-13)^2 = 0
Hence, x = 3 and x = 4 and x = 13
Since only first option is the multiple of 13.
it would be the answer.
- option.