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Fractal
- Master | Next Rank: 500 Posts
- Posts: 183
- Joined: Sun Aug 22, 2010 1:02 am
- Location: Switzerland
- Thanked: 5 times
(2^0.5 + 5^0.5)^2
a) 7
b) 10
c) 13
d) 15
e) 17
Who knows a good way to solve this?
I did it like this, but I think there could be quicker ways:
1. step: 2^0.5 = 1.41 (everybody should know that without calculation)
2. step: 5^0.5 = approximately 2.2 (just by "guessing")
3. step: (1.41 + 2.2) = 3.6
4. step: 3.6^2 = 12.96 (calculation) --> so go with c)
a) 7
b) 10
c) 13
d) 15
e) 17
Who knows a good way to solve this?
I did it like this, but I think there could be quicker ways:
1. step: 2^0.5 = 1.41 (everybody should know that without calculation)
2. step: 5^0.5 = approximately 2.2 (just by "guessing")
3. step: (1.41 + 2.2) = 3.6
4. step: 3.6^2 = 12.96 (calculation) --> so go with c)
