Let pqr be a three digit number. Then, pqr+qrp+rpq is not divisible by
9
pqr=100p+10q+r
qrp=100q+10r+p
rpq=100r+10p+q
Adding all three,
⇒ pqr+qrp+rpq=100(p+q+r)+10(p+q+r)+(p+q+r)
=111(p+q+r)
=37×3(p+q+r)
(pqr+qrp+rpq)is divisible by 37,3and(p+q+r)