Answer: 56
Step-by-step explanation: 100 multiplied by 50% is 50 + 12% =56
30 + 8 = 38 desks
38 x 4 = 152 legs
If you did not add those eight desks then you will have 120 legs.
So, the amount of legs will go up by 32 if you add 8 more desks.