ElectricPavlov

Slope of the original line is   2-4  / 1-7 =  1/3

y = mx + b     

2 = 1/3 (1) + b   b= 5/3

original line is     y = 1/3 x + 5/3      perpindicular slope is   -3

Midpoint of original line is 4, 3

New line    3 = -3(4) + b    b = 15

New perpindicular line    y = -3x + 15 

Here is a graph:

https://www.desmos.com/calculator/nljlb5kiy8

or   +31    since it has to be positive     31   32  and 33

I'll try:

THere is a 95% chance that you DO order a sandwich or soup

.95 x .8 x .7 = 53.2 %      (I usually get probability questions incorrect !)

Note that most 'Answerers' are less inclined to provide methods of finding an answer to 'guest' posters and may just post  an answer.....

    Ever thought of signing up as a registered user?    ~EP

b=11.25/a     (from first equation)

c=36/b = 36a/11.25

ac=20

a  * [36a / 11.25] = 20

solve for a =15/6

c= 36a/11.25 = 36(15/6) /11.25 = 8

Volume of a cylinder   pi r² h

1/5 full   is the   1/5 pi r^2 h

add 3 liters

1/5 pi r^2 h+ 3   =  1/4 pi r^2 h

3 = (1/4 - 1/5 ) pi r^2 h

3 = 1/20 pi r^2 h

60 liters = pi r^2 h = volume when full

h(t)=-4.9t^2+14t-0.4       substitute  6 in for h(t) and solve for t

    you should get two VALUES for t   the ball is above 6m for the time in between

6 = -4.9t^2+14t-.4

-4.9t^2 +14t- 6.4 =0    solve for t = 0.571429   and   2.28571    now you calc the time the ball is above 6m

Since the do an out and back trip....the up and down portions reverse and the flat remains the same

ANSWER 24 MPH

example:   on the way out   say    60 m up hill   = 3 hours

                                                     flat     48       = 2 hrs'

                                                     down  120    = 4 hrs

on the way back                           up 120          = 6 hrs

                                                     flat 48           = 2

                                                     down 60      = 2                          total miles 456 miles

                                                                                                        total time = 19 hrs                 avg m/h = 456/19 = 24 m/hr