Length is increased so the new length would be 1.1L
The width is decreased by p percent, which now becomes 1-P/100
The new area = 1.1l x (1-P/100)
The area decreases by 12 percent, so the new area = 0.88A
Noe you have 0.88A = 1.1L * (1-P/100)
Simplify to get 0.8 = 1-P/100
Solve for P to get 0.2
Multiply by 100 for the percent: 20%
The answer is C.