Bihar Police Constable Model Paper 7

Concept:
To find the unit digit of the resultant number, just consider the unit digit of each number.
Calculation:
${\left(1068\times 486\times 928\right)}^2$
Taking unit digit
${\left(8\times 6\times 8\right)}^2$ = ${\left(384\right)}^2$
⇒ $4^2$
⇒ 4 × 4
⇒ 16
∴ Unit digit is 6.