NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 13: Statistics and Probability - Exercise 13.3

Question 40

Total items:

There are 48 mobiles in total.

Step 1: Find probability for Varnika.

• Varnika buys only good phones.
• Number of good phones = 42.
• Total phones = 48.
• So, probability = \(\dfrac{\text{favourable outcomes}}{\text{total outcomes}} = \dfrac{42}{48}\).
• Simplify: \(\dfrac{42}{48} = \dfrac{7}{8}\).

Step 2: Find probability for trader.

• The trader sells all phones that do not have a major defect.
• Phones with major defect = 3.
• So, acceptable phones = Total – Major defects = 48 – 3 = 45.
• Total phones = 48.
• So, probability = \(\dfrac{45}{48}\).
• Simplify: \(\dfrac{45}{48} = \dfrac{15}{16}\).

Final Answer:

(i) For Varnika = \(\dfrac{7}{8}\)

(ii) For trader = \(\dfrac{15}{16}\)