[10分] Maths Questions (Rate and Ratio) 要列明步驟 ^ ^

1) area of room on the plan = 3.2x2.6 = 8.32cm^2
actual length of room = 3.2x300 = 960cm
actual width of room = 2.6x300 = 780cm
actual area of room = 960x780 = 748 800cm^2
therefore required ratio=
8.32 : 748 800
= 1: 90 000

2) Let x be the amount each bucket can hold
Amount of flour in first bucket = (3/4)x
Amount of sugar in first bucket = (1/4)x
Amount of flour in second bucket = (5/6)x
Amount of sugar in second bucket = (1/6)x
Total amount of flour = (3/4+5/6)x = (19/12)x
Total amount of sugar = (1/4+1/6)x = (5/12)x
Therefore ratio of flour to sugar in large container=
(19/12)x : (5/12)x
= 19 : 5

1) since the scale of the plan is 1:300 & the room is rectangular:

hence the ratio of the area of the room on the plan to its actual area = (1/300)(1/300)
=1/90000 = 1:90000

2) first bucket contains the ratio of flour to sugar = 3:1
hence total parts = 1+3 = 4

second bucket contains the ratio of flour to sugar = 5:1
hence total parts = 1+5 = 6

therefore total part of flour & sugar in large container = 4+6=10

part of flour in large container = (1+1)/10 = 2/10

part of sugar in large container = (3+5)/10 = 8/10

therefore the ratio of flour to sugar in the large container = (2/10)/(8/10)=2/8=1:4

Shadow.