Question

50% discount + 40% discount=-----discount
A. 60
B. 70
C. 80
D. 90

Answer 1

Hint-When two discounts are given make use of the formula of total discount.

Let x be the first discount =50%
Let y be the second discount=40%
The total discount is given by the formula $\begin{gathered}
   = \left( {x + y - \dfrac{{xy}}{{100}}} \right)\% \\
   = \left( {50 + 40 - \dfrac{{2000}}{{100}}} \right)\% \\
\end{gathered} $
The total discount=$\left( {90 - \dfrac{{2000}}{{100}}} \right)\% = 70\% $
Therefore, we can write 50% discount + 40% discount=70% discount

Note: Do not add up the two given discounts directly ,always make use of the total discount formula when solving problems like these.