Could i please get some help with this, thank you !

Question 1 White light (400 nm 700 nm) diffraction pattern lights up a screen that is 1.10 m away. The diffraction grating has 4'18 slits per mm, which produces a rainbow of diffracted light. What is the width ofthe first order rainbow on the screen? : Question 2 A mirror creates an image that has a height of 0.850 cm that is behind the mirror and 142 cm from the object.The image was created from a 1.70 cm tall object. What is the focal length ofthe mirror