I am having extreme difficulty, could i please get some help ? Thank you !!

Question 1 A blind is pulled down to cover a window but it has a pinhole in it that is allowing sun to enter the room. On a wall that is 1.30 m away you can see a circular diffraction pattern from the pinhole. The central maximum of this circular diffraction has a diameter of 0.700 cm. What is the diameter of the pinhole? ( Hint: Estimate the average wavelength of the sunlight first.) Question 2 A 1.10-cm-tall candle flame is 2.10 m from a wall. You happen to have a lens with a focal length of 30.0 cm, and notice while playing around with it that there are two locations you can place the lens and form a well-focused image of the candle flame on the wall. What is the distance between these two lens locations