Could someone please identify the fastest approach to solving the following:
(0.8)^-5/(0.4)^-4
A. 3/32
B. 5/64
C. 1/2
D. 1
E. 2
Thanks!
(0.8)^-5/(0.4)^-4
A. 3/32
B. 5/64
C. 1/2
D. 1
E. 2
Thanks!
the answer is B.
(0.8)^-5/(0.4)^-4 = (8/10)^-5/(4/10)^-4 = (10/8)^5/(10/4)^4 = 10^5*4^4/8^5*10^4 = 4^4*10/8^5 = 2^8*10/2^15 = 10/2^7 = 5*2/2^7 = 5/2^6 = 5/64
