what's this mean

Question

divide 33 photos into 2 groups so the ratio is 4 to 7

Answer 1

All of these are great answers. Here is yet another approach...

 

Math:

Setup a system of equations to model problem.

 

Two variables:

a = number of photos in group one

b = number of photos in group two

 

Two equations:

a/b = 4/7

a+b = 33

 

Solution:

a = 12

b = 21

 

Note:

The solution can be found by any method of your choice such as substitution, elimination, matrix, or graphing. Plus the general setup above is situated for a calculator with math tools or a computer algebra system. As an instructor I normally want to see mathematical techniques as derived in class, not just a "shoot from the hip" answer albeit correct.

 

Cheers,

Adam

Answer 2

Let's assume the nubers are 4x and 7x and thus 4x+7x= 33 

or 11x = 33

so x= 3 . Hence the numbersw are 4x= 12 and 7x=21 

12 and 21.

Answer 3

You can also do the problem algebraically.

 

If there are x items in the smaller group, then there are 33-x items in the larger group.  

 

Since the groups are in the ratio 4:7, we have 4/7 = x/(33-x)

 

Cross multiply to get 4(33-x) = 7x

 

                             132 - 4x = 7x

 

                                   132 = 11x

 

                                     12 = x

 

There are 12 items in the smaller group and 21 items in the larger.  

Answer 4

There are two groups that when you compare them, there are 4 items in the first group for every 7 items in the second group.  This could be, for example, 4 and 7, 40 and 70, 24 and 42, etc.

 

This problem has a total of 33.  With a ratio of 4 and 7, there are 11 in a set.  This means that 33 could be divided into (33/11)=3 groups of 4 and 7.  That is 12 and 21  (total 33).  The ratio of 4 to 7 is maintained.

Answer 5

ratio 4 to 7

 

Group 1     Group 2

4               7

8               14

12             21      12+21=33

 

mathematically...

4+7=11, 33/11=3, 3*4=12 and 3*7=21

Answer 6

A ratio of 4 to 7 means that for every 4 in one group 7 are in the other group.

Now 4 + 7 = 11. 

So for every 11 photos, 4 go in one group and 7 go in the other.

 

How many groups of 11 are there in 33?

 

 

Answer 7

Think of a model based on the ratio.  The model has 4 items of one type (group 1) and 7 items of another type (group 2).  This makes a total of 11 items.

 

The hint here is that 3 x 11 = 33.

 

Triple the number of items in each of the two groups.  Then Group 1 will have 12 items and Group 2 will have 21 items.  The total number of items will be 33 and the ratio of the items in Group 1 to the items in Group 2 is 12 to 21, i.e. 12/21, which can be simplified to 4/7.