Question

15 DVDs in all. There are 7 comedy DVDs. 4 more drama DVDs than horror DVDs.

Comedy DVDs=____
Drama DVDs=_____
Horror DVDs=______

How do I solve this? I need to explain this to my 4th grader and I can't even figure it out and I'm his mother. Please help.

Answer 1

Comedy = 7; Horror = x ; Drama = x+4 ;
15 = 7 + x + x + 4;
15 = 7 + 2*x +4;
15 - 7 -4 = 2*x ;
4 = 2*x;
x = 4 : 2;
x = 2 ;  ---Horror
2 + 4 = 6    ---Drama

Answer 2

Comedy DVDs=7
Drama DVDs + Horror DVDs = 15 - 7 = 8

You know that the difference between the amount of Drama DVDs and Horror DVDs is 4 and, from sum above, you now know that they add up to 8.  The two numbers are 2 and 6. 

Comedy DVDs = 7
Drama DVDs = 6
Horror DVDs = 2

To check, add them together.