Oxygen is the by-product or waste product of photosynthesis. Plants do not make oxygen just for us.
The race cares produce waste answer by
1. polluting the environment
2.by emitting waste that led to human health problems
The race cares generate waste which led to pollution of environment. The use of motor oil, brake fluid and leaded gasoline led to production of toxic chemicals These chemical have been shown to cause cancer, birth defect and kidney problems.
Light speed in water is 2.25 times 10^5 m/s so the index of refraction is higher than the index of refraction of light in a vacuum which is 1.0. (speed in vacuum for light is 300,000 km/s)
Index of refraction of light in water is 3.0 time 10^5 m/s divided by 2.25 times 10^5 m/s = 1.33.
Hope this is what you wanted.
Basically 1 out of 52 is a percentage. So, 1 is equivalent to 5.2% out 52, and if you choose one number your likely hood of it being right is 5.2%
