Question

At 1 p.m., the work crew starts at the intersection of New Street and Main Street and moves toward the intersection of Main Street and Wilson Street, painting lane lines at an average speed of 5mi/h. The work crew will take its afternoon break when it is 3 mi from the intersection of Main Street and Wilson Street. Determine what time the work crew will take its afternoon break.Hints: you will need to use these equations: D=RT, y=mx+b and m=y1-y2/x1-x2 One more hint, draw the above image on graph paper, and make the intersection of North St. and Wilson St. the origin. Then you can make a bunch of linear equations to represent the roads. Find points of intersection of the lines. And use the points of intersection, with D=RT find out when the crew took their afternoon break.

Answer 1

From the question given

D = RT

D= distance in miles

R = rate in miles/hr

T = time in hour

d = 3miles

R = 5mi/h

since D = RT

make T the subject of the formula by dividing both sides by R

D/R = RT/R

T = D/R

T = 3 / 5

T = 0.6 hours

convert the hours to mins

60 mins ===== 1h

xmins ======== 0.6h

cross multiplication

x * 1 = 0.6 x 60

x = 36 mins

since the crew started work by 1pm, therefore they will have their break exactly 1h 36mins, that is 36 mins after they started the work