Answer:
time taken for 25% Phlebotinum and 75% Dilithium is 168 million years
Explanation:
radioactive isotope of Phlebotinum decays into Dilithium.
time taken to half life takes = 42 million years
half life means that the Phlebotinum is 50% and Dilithium is also 50%
and now it is given that Phlebotinum is 25% and Dilithium is 75%
hence this condition will come after two half lives.
for one half life it takes 42 million years
and for second half life time becomes 4 times of first half life
time for 25% Phlebotinum and 75% Dilithium is = 4 × 42
= 168 million years.
hence time taken for 25% Phlebotinum and 75% Dilithium is 168 million years
