Mark and John Are 10-Year-Old Twins Who Do Not Get

question 65

Essay

Mark and John are 10-year-old twins who do not get along. They have opened separate lemonade stands and are competing with each other, selling lemonade on their block. Their mother observes that Mark is very good at making lemonade and John is an excellent young salesman. She suggests they both could make more money if they worked together. John counters that two stands will always make more money than one. Who is right? Why?

---

Definitions:

Pacinian Corpuscles

Specialized nerve endings in the skin and viscera that detect mechanical pressure or vibrations.

Statocysts

Sensory organs found in some aquatic invertebrates, such as crustaceans and mollusks, used to sense gravity and enable balance and orientation.

Lateral Line Organs

A system of sense organs found in aquatic vertebrates, used to detect movement and vibration in the surrounding water.

Stereocilia

Hairlike projections on the surface of certain cells, involved in sensory reception, particularly in the inner ear for hearing.