Successive discounts of 10%,12% and 15% amount to a single discount of -

Explanation:-

Let marked price be Rs. 100
Then,
S.P. = 85% of 88% of 90% of Rs. 100 $$\eqalign{ & = {\text{Rs}}{\text{.}}\left( {\frac{{85}}{{100}} \times \frac{{88}}{{100}} \times \frac{{90}}{{100}} \times 100} \right) \cr & = {\text{Rs}}.67.32. \cr}$$ ∴ Single Discount
= (100 - 67.32)% = 32.68%