Answer:
The actual discount is a 68% discount.
Step-by-step explanation:
Remember that if something has a price P, and you have a discount of the X%, the new price will be:
P' = P - P*(X%/100%) = P*(1 - X%/100%)
Here we first have a 60% discount, then if the initial price is P, the new price is:
P' = P*(1 - 60%/100%) = P*(1 - 0.6)
Now we have an additional 20% discount (this applies to the new price)
then the final price is:
P'' = P'*(1 - 20%/100%) = P'*(1 - 0.2) = P*(1 - 0.6)*(1 - 0.2)
We want to rewrite this as something like:
P'' = P*(1 - k)
Let's do this:
P'' = P*(1 - 0.6)*(1 - 0.2) = P*(1 - 0.2 - 0.6 + 0.2*0.6)
= P*(1 - 0.8 + 0.12) = P*(1 - 0.68)
And this can be as:
P'' = P*(1 - 68%/100%)
Then the actual discount is a 68% discount.
