Problema Solution
The IQ of a Thoronian varies directly with the square of the number of teeth it has. If a Thoronian with 5 teeth has an IQ of 75, find the IQ of a Thoronian with 8 teeth.
Answer provided by our tutors
y varies directly with x (or: "x and y are directly proportional") if there is a constant k such that: y = kx
In our case we have: 75 = k*5^2
by solving we find k = 75/25 follows k = 3. thus the formula for the IQ is:
y = 3*x^2, where y is the IQ, x is the number of teeth
for x = 8 teeth we have
y = 3*8^2
y = 3*64
y = 192
The IQ of Thoronian with 8 teeth is 192.