2^z - 2^z-3=224
This means
2^z - 2^z/2^3=224
2^z-2^z/8=224
8(2^z)-2^z=224*8
7(2^z)=224*8
224*8=7*32*8=7*2^8
Hence z=8
gmat prep question
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
-
Cybermusings
- Legendary Member
- Posts: 559
- Joined: Tue Mar 27, 2007 1:29 am
- Thanked: 5 times
- Followed by:2 members
2^z - 2^z-3=224
Taking 2^z-3 common
2^z-3 [ 2^3 - 1] = 224
2^z-3 [7] = 224
2^z-3 = 224/7 = 32
2^z-3 = 2^5
z-3 = 5
Hence z = 8
Taking 2^z-3 common
2^z-3 [ 2^3 - 1] = 224
2^z-3 [7] = 224
2^z-3 = 224/7 = 32
2^z-3 = 2^5
z-3 = 5
Hence z = 8
