We are given that
\(P(agate) = \frac{1}{6}\)
When dice is thrown \(P\) times, the probability of the agate stone appearing all P times is x.
This can be written as,
P(agate appearing P times) = P(agate) X P(agate) X P(agate) X .... P times
because each dice role is independent from the previous one.
\(x = [P(agate)]^P\)
\(x = (\frac{1}{6})^P\)
When dice is thrown \(Q\) times, the probability of the agate stone appearing all Q times is y.
This can be written as,
P(agate appearing Q times) = P(agate) X P(agate) X P(agate) X .... Q times
\(y = [P(agate)]^Q\)
\(y = (\frac{1}{6})^Q\)
Now, \(x < y\)
And as we are working with number between 0 and 1, lower power means larger number.
Ex. \((\frac{1}{2})^2\) = \(\frac{1}{4}\) and \((\frac{1}{2})^3\) = \(\frac{1}{8}\) and \(\frac{1}{4} > \frac{1}{8}\)
So,
if \(x < y\) then \(P > Q\)
Also,
\(\frac{1}{x} + \frac{1}{y} = 7992\)
Using values of x and y,
\(1/(\frac{1}{6})^P + 1/(\frac{1}{6})^Q = 7992\)
\(6^P + 6^Q = 7992\)
Now looking at the options, we can be sure that value of P and Q will be between 1 to 6.
And we also know P > Q.
Looking at all the \(6^n\) for n between 1 to 6 we get,
\(6^1 = 6\), \(6^2 = 36\), \(6^3=216\), \(6^4= 1296\), \(6^5=7776\), \(6^6\) will be greater than \(10000\) so we don't need to check.
Looking at \(6^5\)=7776 we can see it is closest to \(7992\) and substracting it from \(7992\) gives us \(216\).
So,
final answer
\(P = 5\) and \(Q = 3 \)