ANSWER
In 16 years time.
EXPLANATION.
If the number of subscribers is 324 million, then it means
But we were given that,
This implies that,
We now solve for t,
That will be approximately in the 16th year.
64,513; 10; 2,402. The 4 in 64,513 is essentially 4,000 whereas the 4 in 2,402 is only 400. 400(10)=4000.
I believe that you would just multiply 2.35*5 and that would be your answer.
=11.75
Do what the problum ids telling you than apply it to the math and you will always get the right answer