A He-Ne laser produces 633 nm light. When it passes through a diffraction grating with d=5.55 x 10^-6 m, what is the angle of its third order (m=3) maximum?

"if the pressure acting on an ideal gas at constant temperature is tripled, its volume isa) reduced to one-third.b) increased by a factor of three.c) increased by a factor of two.d) reduced to one-half"