Please provide an explanation with your answer, thank you!

the answer is c. because the awnser is 47.5 and round upto the nearest whole number si 50

Step-by-step explanation: if the yard stick is  3ft and the shadow is 4ft that means the shadow of the stick is 1ft longer than the stick itself.

so if the shadow of the flag pole is 20ft than you -1 and get 19 as shown "20 - 1 = 19" then it said the rope needs to be 2.5 times as long as the pole so you multply 19 by 2.5 as shown "19 x 2.5 = 47.5" round up its 50ft. so there you go hope it helped let me know

the barter