Question

Rajesh has just bought a VCR from Maharashtra Electronics and the shop offers after sales service contract for Rs. 1000 for the next five years. Considering the experience of VCR users, the following distribution of maintenance expenses for the next five years is formed.

The expected value of maintenance cost is :

• A. Rs. 800
• B. Rs. 770
• C. Rs. 700
• D. Rs. 900

Hint:

When adding up long decimal products mentally, combine terms that share clean sums. For example, $125 + 125 = 250$, and $150 + 150 = 300$. Grouping elements makes calculation smooth and less prone to simple errors under test pressure!

Answer 1

The Correct Option is B

Step 1: Recall expected value.
The expected cost is the sum of each cost times its probability, $E(x) = \sum p_i x_i$.

Step 2: Multiply and list.
The products are $0, 125, 150, 150, 160, 125, 60$ for the costs 0, 500, 1000, 1500, 2000, 2500, 3000.

Step 3: Add them.
The total is $0 + 125 + 150 + 150 + 160 + 125 + 60 = 770$.
\[ \boxed{\text{Rs. 770, option 2}} \]