1
Total possible outcomes when throwing two dice = 6 × 6 = 36
2
Find favorable outcomes for sum = 7
(1,6), (2,5), (3,4), (4,3), (5,2), (6,1) = 6 outcomes
3
Apply formula = 6/36 = 1/6
Answer: 1/6
Shortcut Trick #3 - Dice Sum Patterns: For two dice, sum of 7 has maximum probability (6/36), while sums of 2 and 12 have minimum probability (1/36 each).
Common Mistake #1: Students often forget to consider all possible arrangements. For example, when drawing 2 balls from a bag, they count (Red, Blue) but forget (Blue, Red) as a separate case when order matters. Always check whether the problem requires considering order or not.
Another frequent error is mixing up 'with replacement' and 'without replacement' scenarios. In 'with replacement', the total number of items remains the same for each draw. In 'without replacement', the total decreases after each draw, affecting subsequent probabilities.