The marked price of a book is Rs. 900. A man bought the same for Rs. 693 after getting two successive discounts, the first being 12%. What was the second discount rate?

Correct option is D

Given:

MP of a book is Rs.900

SP of a book is Rs.693

Formula Used:

Equivalent discount = a + b – ($$\frac{ab}{100}$$​)

where, a is the first discount.

b is the second discount.

% Discount = $$\frac{(MP-SP)}{MP} \times 100$$​​

Solution:

% discount = $$\frac{(900-693)}{900} \times 100$$​​

% discount = $$\frac{207}{90} \times10$$​​

% discount = 23

Equivalent discount = a + b – $$\frac{ab}{100}$$​​

=> 23 = 12 + b – (12 × b/100)

=> 11 = b – 0.12b

=>11 = 0.88b

=> b = $$\frac{11}{0.88}$$​​

=> b = 12.5

The rate of the second discount is 12.5%.

Thus, correct option is (d)