Which single discount will be equal to two successive discounts of 20% and 10% ?

pls make it soo easy I have no idea about this!

rosala
Mar 3, 2015

#1**+10 **

OK, let's assume that you startd with $100.

The first discount of 20% is $20, leaving you with $80.

The next discount of 10% (of $80) is $8, for a total discount of $28.

This could have been achieved with one discount of 28%

Guest Mar 3, 2015

#3**+10 **

Let's look at it this way, rosala....

Something costs $1 but you have a 20% discount.....so 20% of $1 is .20

So far....we would pay ...... $1 - .20 = .80

Now....let's apply the second discount.....this is 10% of .80

And 10% of .80 = .08

So.....this means that we get .08 off of .80 = .80 - .08 = .72

Now, notice that the total discount is .20 + .08 = .28.......which is just 28% of one dollar

So....we got a total discount of 28%

Does that help??

CPhill
Mar 3, 2015

#4**0 **

It does but... How do I write it in the exam! I can't write it in an explaining way.... I will have to write it in. A practical way!

rosala
Mar 3, 2015