First, you would need to determine how many questions he got correct.
30 - 12 = 18
Next, you would need to create an equation for this problem. Let x represent the unknown percentage.
= 
Now, you would cross multiply.
30x = 1,800
The last step would be to isolate the x. To do this, you would divide both sides of the equal sign by 30.
x = 60
Ahmad got 60% of the questions correct.
I hope this helps!
30 - 12 = 18
Next, you would need to create an equation for this problem. Let x represent the unknown percentage.
Now, you would cross multiply.
30x = 1,800
The last step would be to isolate the x. To do this, you would divide both sides of the equal sign by 30.
x = 60
Ahmad got 60% of the questions correct.
I hope this helps!