The following coordinates represent a parallelogram.
So 3 bus tickets 3(64) = $192
and 4 train tickets 4(82) =$328
add them together 192+328 =520
it would cost $520 to buy 3 bus tickets and 4 train tickets
The fourth term of the binomial expansion
can be calculated using the formula for (i+1)-th term of the binomial expansion:

In order to find term
, determine that

Now

Answer: correct choice is A