The value of (1018)2 − 1019 × 1017 + 1015 × 1012 − 1016 × 1011 is:

1 4 3 5

5

Do this question with unit digit concept for saving time because all the numbers are near to 1000 82 - 9 × 7 + 5 × 2 - 6 × 1 = 4 - 3 + 0 - 6 = -5 10 - 5 = 5 The answer has unit digit of 5.  Hence, option 4 is correct.