If the original price is $40 and the discount price is $25, what is the percent discount?

37.5%

Step-by-step explanation:

Ok I always do these problems in a weird way cuz im autistic but here's my process...

10% of 40 is 4

5% of 40 is 2

2.5% of 40 is 1

4 goes in to 25 6 times

4x6=24

which is one less than 25

so there's six 10%s which is 60%

plus the extra 2.5%

so it's 62.5%

so the item is 37.5% off...

36

step-by-step explanation:

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)