Answer:
x = 12
Step-by-step explanation:
Angle QPR + Angle PQR = Angle HRQ

Honestly, I don't think there is a certain method or anything to find how much candy corn there is in that jar. Try counting and rounding or just take a solid guess ! You'll maybe be closer to the answer by taking a solid guess ! Good luck :)
You can see solution in the picture, hope that can help you :-)