Scout and Heavy

A scout and a heavy are pushing a crate forwards. The scout pushes with a force of $100\text{ N}$ and the heavy pushes with a force of $500\text{ N}$ . The crate has a mass of $60\text{ kg}$ , and the kinetic friction coefficient between the ground and the crate is 0.25. Calculate the acceleration of the crate in $\text{m/s}$ .