Others hav shown their ideas how to solve ur prob..
Im just wanna explain how chmod works. It is mapped in binary.
Mayb, it isn't importante to know this, just for ur info...

r= read
w= write
x= execute

(Binary)
r | w | x (Decimal)
0 | 0 |0 = 0
0 | 0 |1 = 1 (you ticked on x)
0 | 1 |0 = 2 (you ticked on w)
0 | 1 |1 = 3
1 | 0 |0 = 4 (you ticked on r)
1 | 0 |1 = 5
1 | 1 |0 = 6
1 | 1 |1 = 7 (you ticked everything)

So if u assigned chmod 704 filename, it is likely u assigned 111 000 100 for owner, group and others..