What are the key Layers to way of thinking?

By what percent will the product of two numbers change, if the first number increases by 70%, while the second number decreases by 40%.

Match the scsi standard to the definition that best describes it. 1. also called ultra scsi; has a transfer rate up to 30 mbps and 8-bit bus 2. transfer rate of 5 mbps and 8-bit bus 3. also called firewire; has a transfer rate up to 100 mbps and can connect up to 63 devices 4. consists of two protocols; fast scsi with speeds up to 10 mbps using an 8-bit bus and wide scsi, which uses 16- or 32-bit buses serial scsi scsi-2 scsi-3 scsi-1

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.