Question

How many positive integers $\le 462$ are relatively prime to $462$?

Answer 1

$462=2\times 3\times 7\times 11$

Total positive numbers relatively prime to $462=462-$numbers which are not relatively prime to 462

$=$$462-({}^4{C}_1+{{}^{4}C}_2+{{}^{4}C}_3+{{}^{4}C}_4)$

$=$$462-(4+6+6+4)$

$=$$462-20$

$=$$442$