45% of the total = 9
.45(x) = 9
divide both sides by .45
x = 9/.45
That will give you the total distance.
subtract 9 from that answer to get how much farther.
Ivan has completed 45% of his walk. He has already walked 9 km. How much farther does he have left to walk?
I don't understand how to do this. Could you please help and show me how you got this answer? Thank you.
2 answers
45% is just about half. So, you know right off he has about 9km left to go. (This is just for a sanity check)
So, the whole walk is 9/.45 = 20km
20-9 = 11 km left to go
The key idea here is figuring the total distance if you know some of it and the % that represents.
If you want to know what to divide by what, think of something easy.
If 9 kn were half the distance, the whole would be 18km, right?
That is 9 / (1/2) = 9*2 = 18
But you only have 45%, or .45
So, divide by .45 -- you expect a number a little more than 18.
Knowing a part and the fraction it represents, just divide the part by the fraction. Play around with some values till you feel comfortable with the idea.
So, the whole walk is 9/.45 = 20km
20-9 = 11 km left to go
The key idea here is figuring the total distance if you know some of it and the % that represents.
If you want to know what to divide by what, think of something easy.
If 9 kn were half the distance, the whole would be 18km, right?
That is 9 / (1/2) = 9*2 = 18
But you only have 45%, or .45
So, divide by .45 -- you expect a number a little more than 18.
Knowing a part and the fraction it represents, just divide the part by the fraction. Play around with some values till you feel comfortable with the idea.
22 answers