A positive feedback loop is a system that occur in nature when production of a specific reaction leads to increase in its own production or reaction. Oxytocin is an example of the positive feedback loop as the release of its higher concentration.
Contraction of the uterus cause the release of the oxytocin that leads to more contraction which lead higher concentration of the hormone. So the positive feedback loop cause the shift in the system, far from the equilibrium.
Sometimes breaking down a question helps us answer the question. The general question to be answered here is "What is 2/3 of 7/8?". We can solve this by multiplying the fractions together. 2/3 times 7/8 gives us 7/12.
