Ivan has 6 times as many blue beads as red beads. he has 49 red and blue beads in all. how many blue beads does ivan have?

The light bulb (A) destroyed the first market for petroleum.

Before the invention of light bulbs, petroleum rather than electricity was used to light homes, streets, and everything in between. After the light bulb became common place, the need for gas lighting diminished, therefore effectively destroying the first market for petroleum.