Answer:

Step-by-step explanation:
x= 1 over 4y-2
If it is packed 2/5 in 1/2 minutes
1 minute =2/5*2=4/5 or 0.8 boxes/min
1/8 of all=mystery
mystery=3
'of' means multiply
therefor
1/8 times all=3
multiply both sides by 8/1 to clear fracion
all=24
Each question is worth 4 points (100/25=4)
Therefore, when you divide 83 by 4, you get 20.75, as as he's aiming to get a B, this needs to be rounded up to 21.
Xio would need to get 21 questions right to get a B, hope this helps :)