5! Is the same as 5x4x3x2x1 and 4! Is the same as 4x3x2x1 because 4! Is in the denominator it cancels the 4x3x2x1 in the numerator and you are left with 5x(3!) witch is the same a 5x3x2x1. The answer=30
First find the area of the circle then divide it by 4
Find 20 percent of $20 by multiplying 0.20 x20
You get $4. That’s what he saved.