Question

An expression that models the number of mongoose on a small Caribbean island in terms of y. The number of years after 1950 is 520 + 8y. Identify which of the following statements is incorrect.

a) The number of mongoose on the island increases by a constant amount each year.
b) The number of mongoose on the island in 1950 is 520.
c) The number of mongoose on the island in 1950 is 512.
d) The number of mongoose increases by eight for each year after 1950.

Answer 1

The expression provided is used to model the mongoose population as a function of the years after 1950. The incorrect statement in the choices given is that the number of mongooses on the island in 1950 is 512; the correct number should be 520 as indicated by the expression 520 + 8y when y=0.

Step-by-step explanation:

The correct expression to model the number of mongooses on a small Caribbean island in terms of y, the number of years after 1950, is given by 520 + 8y. Now let's analyze which statement is incorrect about this model:

• The number of mongooses on the island increases by a constant amount each year - This is true as per the model; it increases by 8 each year.
• The number of mongooses on the island in 1950 is 520 - This is correct; when y = 0, the expression equals 520.
• The number of mongooses on the island in 1950 is 512 - This is incorrect; the expression clearly states 520 for 1950, not 512.
• Mongooses increase by eight for each year after 1950 - This is true; the value 8y indicates an increase of 8 per year.

Therefore, the incorrect statement is c) The number of mongooses on the island in 1950 is 512.