Two masses M1, and M2 are attached to the ends of a string which pass over a pulley attached to the top of a double inclined plane of angles of inclination `alpha` and `beta`. If M2 > M1, the acceleration a of the system is given by

`(M_2 (sin beta)g)/(M_1 + M_2)`
`(M_1(sin alpha) g)/(M_1+M_2)`
`((M_2 sin beta - M_1 sinalpha)/(M_1 + M_2))g `
Zero