CBSE Class 12 Mathematics 2023: question 35(b)

Hints

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Step-by-step solution

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1. Let $X$ be the prize value (in ₹) on the ticket drawn.

   Then $X$ can take the values $8$, $4$ and $2$.

   1 mark

2. Probabilities, out of 10 tickets:

   • $P(X=8)=\frac{2}{10}=\frac{1}{5}$
   • $P(X=4)=\frac{5}{10}=\frac{1}{2}$
   • $P(X=2)=\frac{3}{10}$

   $X$	8	4	2
   $P(X)$	$\frac{1}{5}$	$\frac{1}{2}$	$\frac{3}{10}$
   $XP(X)$	$\frac{8}{5}$	$2$	$\frac{6}{10}$

   3 marks

3. Mean:
   $$E(X)=\sum XP(X)=\frac{8}{5}+2+\frac{6}{10}=\frac{16+20+6}{10}=\frac{42}{10}=4.2$$

   So the mean value of the prize is ₹ 4.20.

   1 mark

Answer: Mean prize = 42/10 = ₹ 4.20

Revise the chapter

• Chapter: Probability (notes, formulas, where marks are lost and every past question)