If a pentagon is rotated 100 degrees will it coincide with itself?

No, it will not coincide with itself.

This is because the angle of rotation is 360/n = 360/5 = 72 degrees instead of 100 degrees. This applies to regular pentagons where the sides are the same length and the angles are the same measure.

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.