Respuesta :
The right answer is 60. M<1 + M<2 + M<3 = 180
50 + 70 + M<3 = 180
120 + M<3 = 180
120 - -120
____ ___
M<3 = 60
50 + 70 + M<3 = 180
120 + M<3 = 180
120 - -120
____ ___
M<3 = 60