sweet treats bakery december 2016

Hi Dear Tutor, I have a question.

Question number 1

Process————-Brownies—————-Muffins——————Cupcakes

Weighing————60(140/40*15)———-45=(90/30*15)———–100=(100/20*20)

Mixing—————-80(140/40*20)———-48=(90/30*16)————-60=(100/20*12)

Baking—————480(140/40*120)————-330-(90/30*110)————600=(100/20*120)

Based on my calculation of Brownies’ hours, it gives different figures for each department, the rest is okay. Why and How?.

I did not understand this part?
140/40*15=52.5
140/40*20=70
140/40*120=420
Could you help me how did they find 60, 80 and 480?