Question: 
Write a function to find t-nth term of geometric series.


Model's Code:
def tn_gp(a, r, t):
    return a * (r ** (t - 1))



Sample Correct Code:
import math
def tn_gp(a,n,r):
  tn = a * (math.pow(r, n - 1))
  return tn


Asserts:
assert tn_gp(1,5,2)==16
assert tn_gp(1,5,4)==256
assert tn_gp(2,6,3)==486


Tests:
Test 1 of 3: FAIL: AssertionError()

Test 55 of 974: 41/55 (74.54545454545455%): failed