Divide I from both sides then subtract r from both sides, too so in the end:
R= (E-r)/I
The 8 full boxes have 80 apples (8x10) and the 6 half boxes have 30 apples (6x5).
So: 80+30=110
E: 36 because the total degrees of a parallelogram is 360 and opposite angles of parallelogram’s are equal so the angles diagonal from the given ones are the same. So the corners are 3x, 2x, 3x, 2x. In total that is 10x. 360/10 = 36
Yes, most likely. You may also find it helpful to plug the pi symbol along with your answer into your (scientific) calculator as it will give you a more accurate response.