The time taken by 18 people to complete a puzzle are shown draw a frequency polygon for the data
time frequency
0 to 10 5
10 to 20 5
20 to 30 7
30 to 40 1

step-by-step explanation:

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50

answer: 8d

step-by-step explanation:

45+5= 50+5=55+5=60

the height of the surface increases from the center out to the sides of the road

it is c!