Question

Prem buys three books from a fair. The cost of the second book is ₹100 more than the first one and ₹300 less than the third one. If the total cost of all the books is ₹1100, find the cost of the second book.

• A. 500
• B. 400
• C. 460
• D. 300

Answer 1

The correct option is D 300

Let the cost of the first book be x rupees.
Then, the cost of the second book = (x + 100) rupees
And the cost of the third book = (x + 100 + 300) = (x + 400) rupees

Given: Sum of the cost of all three books = ₹1100
x + (x + 100) + (x + 400) = 1100
⇒ x + x + 100 + x + 400 = 1100
⇒ 3x + 500 = 1100

Clearly, we have to try with some big numbers here.
If x = 100, $3x+500=3\times 100+500=300+500=800$
If x = 200, $3x+500=3\times 200+500=600+500=1100$
Therefore, if x = 200, LHS = RHS.

Hence, the cost of the second book = x + 100 = 200 + 100 = ₹300