Igcse Model Questions Vol1 2019 Mathematics Question 14

Practice objective / multiple choice question 14 from the 2019 Igcse Model Questions Vol1 Mathematics examination.

Igcse Model Questions Vol1 2019 Mathematics Objective / Multiple Choice Hard Difficulty
Question 14 IGCSE_MODEL_QUESTIONS_VOL1 • 2019 • MATHEMATICS • objective

A box contains 5 red, 4 blue and 3 green balls. One ball is drawn at random, its colour noted, then it is replaced and another ball of the same colour is added to the box. A second ball is then drawn. Let \(X\) be the number of red balls drawn in the two draws. (a) Determine the probability distribution of \(X\). (b) Find the expected value \(E(X)\). (c) Find the variance \(\operatorname{Var}(X)\).

Answer Options

Correct Answer A. P(X=0)=14/39, P(X=1)=35/78, P(X=2)=5/26; E(X)=5/6; Var(X)=245/468
B. P(X=0)=15\/39, P(X=1)=35\/78, P(X=2)=4\/26; E(X)=5\/7; Var(X)=240\/468
C. P(X=0)=13\/39, P(X=1)=36\/78, P(X=2)=5\/26; E(X)=4\/6; Var(X)=250\/468
D. P(X=0)=14\/39, P(X=1)=34\/78, P(X=2)=6\/26; E(X)=5\/5; Var(X)=245\/460
Correct Answer
A
Correct Option:
P(X=0)=14/39, P(X=1)=35/78, P(X=2)=5/26; E(X)=5/6; Var(X)=245/468

About This Question

This is Igcse Model Questions Vol1 2019 Mathematics Question 14. It is one of the objective questions from the 2019 Igcse Model Questions Vol1 Mathematics examination.

Difficulty level: Hard .

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