Explanation

Total balls = 4 red + 5 blue + 6 green = 15 balls

Ways to draw 2 balls from 15 = C(15,2) = 15×14/2 = 105  

Ways to draw 2 green from 6 = C(6,2) = 6×5/2 = 15

Probability both green = 15/105 = 1/7

Last verified on 13-06-2026

Explanation

When a die is rolled twice, total outcomes = 6 × 6 = 36

We need sum > 9, so sums 10, 11, 12

Sum 10: (4,6), (5,5), (6,4) → 3 ways  

Sum 11: (5,6), (6,5) → 2 ways  

Sum 12: (6,6) → 1 way  

Total favorable outcomes = 3 + 2 + 1 = 6

Probability = favorable / total = 6/36 = 1/6.

Last verified on 10-06-2026

Explanation

3 coins → total outcomes = 2³ = 8

Exactly 2 heads: HHT, HTH, THH → 3 outcomes

Probability = favorable / total = 3/8

Last verified on 09-06-2026

Explanation

• Mean = (4 + 7 + 8 + 10 + 12) ÷ 5
• Mean = 41 ÷ 5 = 8.2
• Mean is the average value of a data set.

Last verified on 08-06-2026

Explanation

Sample space when rolling a dice: {1, 2, 3, 4, 5, 6} → 6 outcomes

Numbers divisible by 2: {2, 4, 6}  

Numbers divisible by 3: {3, 6}

"Or" means union. Combine them but don't double-count 6:  

Divisible by 2 or 3 = {2, 3, 4, 6} → 4 outcomes

Probability = Favorable / Total = 4/6 = 2/3

Formula way: P(A∪B) = P(A) + P(B) - P(A∩B) = 3/6 + 2/6 - 1/6 = 4/6 = 2/3

Last verified on 08-06-2026