Word problem

Question

CARY USED 7 LEMONS TO MAKE 3 QUARTS OF LEMONADE.  AT this RATE How Many Lemons Will CARY Need To Make 16 Quarts Of Lemonade?

Answer 1

Think proportions

 

if 7 lemons make 3 qrts

then x lemons make 16 qrts

 

7/3=x/16

 

7  = x

-      -

3      16   (Cross multiply)

 

3x=112

 

x=112/3= 37.33

so 16 qrts uses 37.33 lemons (note .33 is same as 1/3)

Answer 2

7 lemons for 3 quarts is how many lemons for 16 quarts? 

 

You could notice that three goes into sixteen five and a third times and so the answer will be seven, five and a third times or 7 x (5 + 1/3) = 35 and 7/3 or 37 and 1/3.

 

Or a good way to solve these is to make a pair of ratios. Assuming it always takes the same amount of lemons to make the same amount of quarts the ratio of 7 to 3 should be the same as the number of lemons you're trying to find to 16.

 

That is 7/3 = ?/16.

 

Read this as "something divided by sixteen is 7/3, so that something must be 16 times 7/3". Crunch that out and you should get 37 and 1/3. 

 

I wish this thing let you write fractions and mixed numbers better. That would be good for a tutoring website.