In one day, a store sold 2/3 as many DVDs as blue-ray discs. The total number of DVDs and Blu-ray Discs sold that day was 280. How many DVDs were sold ?

Question

I need help 

Answer 1

2/3 as many DVDs as blue-ray discs

 

d = (2/3)(b)

 

The total number of DVDs and Blu-ray Discs sold that day was 280

 

d + b = 280, d = 280 - b

 

Substitute:

d = (2/3)(b)

280 - b = (2/3)(b)

280 = 5/3(b)

b = 168

d = 112