Finding the limiting factor

You will write the model leaf of Blackman's law. The rate is the smaller of what the light allows and what the carbon dioxide allows. Then you will find the factor that limits each set of conditions.

The idea. The light allows $10$ times the light intensity in percent, but never more than $100$. The carbon dioxide allows $0.25$ times its concentration in microlitres per litre.

Your tasks.

1. In rate, return the smaller of the two numbers that the light and the carbon dioxide allow.
2. In limiting, return "light" when the light allows less than the carbon dioxide, and "carbon dioxide" otherwise.
3. Set light_limited to the number of conditions in conditions that are limited by light.