Answer:
Santosh purchased 4 new and 4 used DVDs.
Step-by-step explanation:
From the information given, as you know that Santosh spent $200 and that the DVD player cost $120, you can say that the new and used DVDs cost $80, which can be expressed as:
15x+5y=80, where:
x refers to the number of new DVDs
y refers to the number of used DVDs
Now, as the statement indicates that Santosh purchased the same number of new and used DVDs, this means that x is equal to y and you can replace y with x and solve for x:
15x+5x=80
20x=80
x=80/20
x=4
According to this, the answer is that Santosh purchased 4 new and 4 used DVDs.