Find brings back empty matrix

When I use the find command the get back empty matrix: 0-by-1 for B and L,but I get an answer for R. help please thanks

This is my code

clear,clc
load rocket.dat
B= rocket(:,4);
R= rocket(:,2);
L= rocket(:,3);
(find(L<40 & L>60))
(find(B<100 & B>200))
(find(R<115 & R<125))

This is the data in rocket.dat for reference

1.0000000e+000    1.1600000e+002    4.5000000e+001    1.1000000e+002  
2.0000000e+000    1.1400000e+002    4.2000000e+001    1.1500000e+002
3.0000000e+000    1.1800000e+002    4.1000000e+001    1.2000000e+002
4.0000000e+000    1.2400000e+002    3.8000000e+001    9.5000000e+001
5.0000000e+000    1.2600000e+002    6.1000000e+001    1.1800000e+002

Answer 1

[Ahmet Cecen]

That is because a number cant be bigger than 60 and lower than 40 at the same time:

 L<40 & L>60

You need to figure out what range you are actually interested in, and either flip those inequalities or use OR instead of AND.