The answer is 3. Hope this will help.
Answer:
B) 77.5 square feet
Step-by-step explanation:
cut shape into rectangle and triangle
area of rectangle = x*y
area of rectangle = 5*13
area of rectangle = 65
area of triangle = (z-x)*(y-w)/2
area of triangle = 5*3/2
area of triangle = 7.5
Total area = 65 + 7.5
Total area = 77.5, B)
18! is common to each term in the sum:
18! + 19! + 20! = 18! (1 + 19 + 19×20) = 18!×400
The largest prime factor of 18! is of course 17.
Meanwhile,
400 = 16×25 = 2⁴×5²
so the largest prime factor of 18! + 19! + 20! is 17.