1. A pumping machine can pump away 36m^3 water in 20min
(a) Find the pumping rate of the machine in m^3 / min.
(b) A rectangular aquarium of dimensions 27m x 12m x 2.5m is full of water. How long will it take for the pumping machine to pump way 1/3 of the water in the aquarium?
2. By riding a bicycle, Michael can travel a distance of 280m in 25s while Connie can travel 216m in 18s. Whose speed is faster, and by how much?
[15分] Maths Questions (Rate and Ratio) 要列明步驟 =]
2007-08-15 7:26 pm
回答 (2)
2007-08-15 7:36 pm
✔ 最佳答案
(1a)The pumping rate
= 36 ÷ 20
= 1.8 m³/min
(1b)
Volume of the aquarium
= 27 × 12 × 2.5
= 810 m³
1/3 of the water in the aquarium
= 810 ÷ 3
= 270 m³
Time to pump away 1/3 of the water
= 270 ÷ 1.8
= 150 min
(2)
Michael’s speed
= 280 ÷ 25
= 11.2 m/s
Connie’s speed
= 216 ÷ 18
= 12 m/s
Connie is faster then Michael by12 – 11.2 = 0.8m/s
2007-08-15 7:34 pm
1a.36/20=1.8m^3/min
1b.(27x12x2.5/3)/1.8=150min
2.speed of Michael:280/25=11.2m/s
speed of Connie:216/18=12m/s
SO Connie is faster.
1b.(27x12x2.5/3)/1.8=150min
2.speed of Michael:280/25=11.2m/s
speed of Connie:216/18=12m/s
SO Connie is faster.
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