Question

How many black keys would you expect to find on a keyboard with 72 keys in all? Show your work.

Answer 1

Answer:

50 black keys

Step-by-step explanation:

for every set of 7 white keys there are 5 black keys

72/7 = 10

so there is a total of 10 full sets of keys

then you have 2 white keys remaining but that doesn't matter because they will just be on the dies and already have a black key next

so this means that you only have to calculate the number of 10 sets of black keys and thats 5 x 10.

hope this helps : )