Mathematics Exercise

Classwork (05-04-2008)

1. Find the average speed, in km/h, when a car travels

a) 260 km in 3 1/3 h.
answer:

s=d/t
=260km over 3 1/3 h
=260km over 10/3 h(change the 3 1/3 to improper fraction)
=260 km over 3.33333333.....h(3.33333 because 10 divided by 3)
=260 km divided by 3.3333333....h
=78 km/h

b) 418 km in 2h 45 min
answer:

s=d/t
=418 over 2 h 45 mins
=418 over (2h+ 45/60 h)
=418 over 2 3/4
=418 over 11/4
=418 over 2.75
=152 km/h

let me just give the answer:

2.a) s=14.5 over 50min
s=14.5 over 5/6 h(50/60)
=17.4 km/h

b) s=d/t
=14.5 over 50
=14500 over 180000
=29/36 km/h

3.a) d=s*t
=60*2h 15
=60* 2 1/4 h
=540


suk sambung..tired