Jane counted 16 newborns in the hospital nursery. She saw 4 more baby girls than baby boys. How many of each did she see?

Question

I have tried subtracting

Answer 1

There is actually a simpler way of doing this than resorting to two variables.

Let x be your single variable (boys) and so x + 4 =  number of girls. 

 

The equation will be- number of boys (x) + number of girls (x+4) equals 16

 

x + x + 4 = 16

 

2x + 4 = 16

 

2x = 12

 

x = 6

 

6 is your number of boys , 6 + 4 for girls = 10

 

then 6 boys plus 10 girls gives = total 16

 

 

 

 

 

Answer 2

 This is standard problem of  what are 2 numbers whose Sum and their difference are given, and it is given 

  from 3 grade on, in 3rd grade, algebra and variables are not covered, and given by arithmetic.

 

    They normally say in word that if you take 4 away from 16 , you get twice number of boys and nobody knows what are they talking about.

 

   But here if you choose X for boys , and X+4 for girls

 

      X + X + 4 = 16

       2X = 16 -4

     You see that if 4 taken from 16, will come out with twice the number of boys.

 

       So you could see the power of Algebra.

 

    

Answer 3

Start by assigning variables to your unknown numbers:

 

x = number of girls

y = number of boys

 

Read the problem for the first numeric relationship:

"Jane counted 16 newborns in the hospital nursery." So:

x + y = 16

 

Find the next numeric relationship:

"She saw 4 more baby girls than baby boys." So:

x = y + 4

 

Now we have two different equations in two unknowns; we can solve this system of equations by substitution or elimination.

 

Case 1: Substitute y + 4 for x in the first equation:

(y + 4) + y = 16

2y + 4 = 16

    - 4 = -4

--------------

2y = 12

y = 6

Substitute 6 for y in the second equation:

x = 6 + 4 = 10

 

So Jane saw 10 girls and 6 boys.

 

Check: 10 + 6 = 16 and 10 - 6 = 4. √

 

Case 2: Solve by Elimination:

First subtract y from both sides of the second equation:

 

x - y = y - y + 4

 

Now add the first equation to it:

x - y = 4

x + y = 16

------------

2x + 0 = 20; We've "eliminated" y.

x = 10

 

Substitute 10 for x in either equation and solve for y:

10 + y = 16

-10     = -10

--------------

0 + y = 6

 

So we got the same answer with the Elimination Method as we did with the Substitution Method.

Answer 4

girls + boys = 16

girls = boys + 4

 

2* boys +4 = 16 (substitute boys + 4 for girls)

boys = 6 (sovereign prior equation)

girls = 10 (girls = boys + 4)