Answer:
It was destroyed in a fire.
The use of technology has been made much of a convenience to different businesses in order to advertise their products and services. Among which persuasive techniques they most likely use was to let the message be felt by the consumers in which using the product or service would raise their social status in the society.
Working out: 6.25% = 4 half lives (20x4=80ma) 80ma is how old the rock is
