Three blocks of masses 10 kg, 6 kg and 4 kg lie on a frictionless horizontal surface. The masses are connected together by light strings. A string attached to 4 kg block pulls the three blocks horizontally. If the system of blocks is accelerated at 0.5 m/s2, the tension in the string connecting the 4 kg and 6 kg blocks is
1
3 N
2
5 N
3
8 N
4
10 N