Maths Question Help PLEASE!!!?

Question

This is a maths question i am stuck on. The questions are.

Merlin is riding his bike east at a steady 10km/h, while Morgan is riding her bike west at a steady 8km/h. They pass each other on Backpedal bridge at 12 noon. (Assume that east is the positive direction and west is negative and that time before noon is negative and after noon is positive.)

question ( i ) What is the location of each person with respect to the bridge at 9am?

( ii ) What are their locations with respect to the bridge at 2pm?

( iii ) How far apart were they at 10 am?

( iv ) How far apart will they be at 4pm?

PLZ PLZ PLZ SHOW HOW U DO IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!... EXPLAIN CAREFULLY PLZ

THX

Answer 1

West----------bridge----------East

Merlin (10)->           <- Morgan(8) (merlin is driving east, thus starting west of the bridge)

At 12.00, they are on the bridge

i.

At 9.00 (3 hours before 12.00) they are 3 hours away from the bridge.

Merlin drives 10km/hour, so he is 10*3=30km away from the bridge.

Morgan drives 8km/hour, so she is 8*3=24km away from the bridge.

ii.

At 14.00 (2pm) (2 hours after 12.00) they are 2 hours away from the bridge.

Merlin drives 10km/hour, so he is 10*2=20km away from the bridge.

Morgan drives 8km/hour, so she is 8*2=16km away from the bridge.

iii.

At 10.00 (2 hours before 12.00) they are 2 hours away from the bridge.

Merlin drives 10km/hour, so he is 10*2=20km away from the bridge.

Morgan drives 8km/hour, so she is 8*2=16km away from the bridge.

so they are 20+16 km away from eachother.

iiii.

At 16.00 (4 hours after 12.00) they are 4 hours away from the bridge.

Merlin drives 10km/hour, so he is 10*4=40km away from the bridge.

Morgan drives 8km/hour, so she is 8*4=32km away from the bridge.

so they are 40+32 km away from eachother.

If you need more help with this, just let me know.

Answer 2

You will first take the difference in time using

(time in the question minus 12pm[noon])

this equation will give you the time they traveled. (negative time means it happened before noon)

You will then multiply the time to their respective speeds (10km/h for merlin since he is going east[+] and -8km/h for morgan since he isa going west[-])

Now, the answer you will get is their location with respect to the bridge; where: [-]answer is answer km west of the bridge and

                     [+]answer is answer km east of the bridge

that would give you your answer for (i) and (ii)

for questions (iii) and (iv), you simply subtract their distances to see how far they are from each other. you should subtract their distances in this manner: guy on the east most(farther away to the east) - the other guy (DON'T FORGET TO INCLUDE THE SIGNS +/-)

or simply disregard the signs(+/-) then add their locations from the bridge.

(i) 9am - 12pm = -3h

    Merlin: 10km/h * -3h = -30 km = 30 km west of the bridge

    Morgan: -8km/h * -3h = 24 km = 24 km east of the bridge

(ii) 2pm - 12pm = 2h

    Merlin: 10km/h * 2h = 20 km = 20 km east of the bridge

    Morgan: -8km/h * 2h = -16 km = 16 km west of the bridge

(iii) 10am - 12pm = -2h

    Merlin: 10km/h * -2h = -20 km

    Morgan: -8km/h * -2h = 16 km

    distance = morgan - merlin = 16 - (-20) = 36 km apart

(iv) 4pm - 12pm = 4h

    Merlin: 10km/h * 4h = 40 km

    Morgan: -8km/h * 4h = -32 km

    distance = merlin - morgan = 40 - (-32) = 72 km apart