Three blocks of masses m1, m2 and m3 are connected with weightless string and are placed on a frictionless table. If the mass m3 is draged with a force T, the tension in the string between m2 and m3 is
`(Tm_3)/(m_1 + m_2 + m_3)`
`(Tm_2)/(m_1 + m_2 + m_3)`
`((m_1 + m_2)T)/(m_1 + m_2 + m3)`
none of these