What is the correct version of CUDA for my nvidia driver?

I am using ubuntu 14.04. I want to install CUDA. But I don't know which version is good for my laptop. I trace my driver that is:

$cat /proc/driver/nvidia/versionNVRM version: NVIDIA UNIX x86_64 Kernel Module  304.125  Mon Dec  1 19:58:28 PST 2014GCC version:  gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) 

I tried to install CUDA cuda-linux64-rel-7.0.28-19326674 but when I test by command:

./deviceQuery./deviceQuery Starting... CUDA Device Query (Runtime API) version (CUDART static linking)cudaGetDeviceCount returned 35-> CUDA driver version is insufficient for CUDA runtime versionResult = FAIL

Could you help me resolve that problem? I reinstalled my Ubuntu many times.