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MCQ practice · SSC Higher Mathematics Board questions · Chapter 14: Probability

Dhaka Board 2023

When three coins are tossed:

  1. i. the probability of three H = 1/8
  2. ii. the probability of at most two T = 3/4
  3. iii. TTT is a sample point

Think it through first, then pick an option.

  1. a i and ii
  2. b i and iii
  3. c ii and iii
  4. d i, ii and iii
Answer and explanation

Correct answer: b i and iii

i is true: only HHH is favourable out of 8; ii is false: at most 2T means all but TTT, 7 outcomes, probability 7/8, not 3/4; iii is true: it is one of the 8 elements of the sample space.

Why the other options are wrong

  • a i and ii: ii is false (at most 2T means all but TTT, 7 outcomes, probability 7/8, not 3/4), so ii has to be left out; the combination is i and iii.
  • c ii and iii: i is true (only HHH is favourable out of 8), so i has to be in the combination; the combination is i and iii.
  • d i, ii and iii: ii is false (at most 2T means all but TTT, 7 outcomes, probability 7/8, not 3/4), so ii has to be left out; the combination is i and iii.