Well you are at a 86% so t<span>his is considered a "B" grade on an average grade scale. If you take 50 points we would need to know the Total point you could have got in that class to be able to see how much a percent was the assignment work and then take that percentage of the assignment and subtract it from the 86% to see where on the scale you would fall in after the assignment points were taken off. Hope this helps :)
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Answer:
77.14 atm of pressure should be of an acetylene in the tank.
Explanation:

According to reaction, 2 moles of acetylene reacts with 5 moles of oxygen.
Moles of oxygen=
Moles of acetylene =

Volume of large tank with oxygen gas, 
Pressure of the oxygen gas inside the tank = 
..[1]
Volume of small tank with acetylene gas ,
Pressure of the acetylene gas inside the tank = 
..[2]
Considering both the gases having same temperature T, [1]=[2]



77.14 atm of pressure should be of an acetylene in the tank.