When an $\alpha$–particle with kinetic energy K = 11 MeV collides with a stationary lithium nucleus, the following nuclear reaction takes place.

${ }^{4}He{+}^{7}Li{\to }^{10}B+n$

The Q–value of this reaction is E = –2.86 MeV. If the kinetic energy of the neutron outgoing at right angle to the incoming direction of $\alpha$–particle is X MeV and the kinetic energy of boron atom is Y MeV.