What is difference between the sum of tenth terms of a the terms of the AP and GP whose first terms are -2 and 4

Answer 1

for the AP:
sum of 10 terms = 5(-4 + 9d) = -20 + 45d
for the GP:
sum of 10 terms = 4(r^10 - 1)/(r-1)

so I guess their difference would be 4(r^10 - 1)/(r-1) - (45d - 20)

strange question! Am I missing something here?

Answer 2

10