Correct Answer - Option 1 : 3
Given:
All cards marked as 1 on One side
And marked as 2 on Other Side
In one try, we can turn exactly 4 cards.
Calculation:
Initially:
All six cards show ‘1’
1 1 1 1 1 1
First turn:
Turn over four of the '1' cards. Now 4 cards show '2', and 2 cards show '1'.
2 2 2 2 1 1
Second turn:
Turn over three of the '2' cards and one of the '1' cards. Now 2 cards show '2' and four cards show '1'.
2 1 1 1 2 1
Third turn:
Turn over the four cards showing '1'. Now all six cards show '2'.
2 2 2 2 2 2
∴ In 3 tries we can turn all cards to number 2