2) If 20 workers can build a house in 45 days, how many more workers are needed to complete it in 30 days?
А
6
B
15
С
10
D
18

What is 20+(5 x 2/5 )+ 3 show your work

How do you solve a question like this?

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6