If2n=128, then (2n-1)(5n-2)=?
A
2(105)
B
5(105)
C
2(106)
D
2(56)
Correct Answer: 2(105)
Given, 2n = 128⇒2n = 27∴n = 7∴2n - 15n - 2 = 27 - 157 - 2 = 26×55 = 2×105