Flashcards in Ratio Deck (22)

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1

##
Share £50 in the ratio 3:2

(I suggest using a piece of paper and writing this down, but you're lazy so you'll just do it in your head anyway)

###
3 + 2 = 5

£50 / 5 = 10

Each person is worth £10

£30:£20

2

## What are ratios used to do?

### Compare amounts

3

## When is something in direct proportion?

### If quantities increase at the same rate then we say they are in Direct Proportion to each other

4

## If 9 pens cost 63p, how much do 3 pens cost?(ratio, direct proportion)

###
9 pens : 63p

Divided by 3

1 pen = 63/9 = 7p

Times 3

3 pens : 21p

5

## When is something in inverse proportion?

### If one quantity increases at the same rate as another decreases we say they are in inverse proportion to each other

6

## 1 man takes 6 days to paint a house. How long would it take 3 men to paint the house? (Ratio, inverse proportion)

###
1:6

Times 3 | divided by 3

3:2

7

## In ratio what do the units have to be?

### The same

8

## In simple interest, if I have £10 one year and it increases due to simple interest, why is my interest calculated from in the next year?

### The original £10

9

## In compound interest, if I have £10 one year and it increases due to simple interest, why is my interest calculated from in the next year?

### Total money in account (£10+gained)

10

## 1 mile = ?meters = ?km

### 1 mile = 1600meters = 1.6km

11

## 1km = ? Miles

### 1km = 0.62 miles

12

## 1 mm = ?cm = ?meters

### 1mm = 0.1cm = 0.001meters

13

## 1000mm^3 = ?cm^3 = ?m^3

### 1000mm^3 = 1cm^3 = 0.000001meters^3

14

## 1mm^3 = ? = ?meters ^3

### 1mm^3 = 0.001cm = 0.000000001m^3

15

## 1 gallon = ?litres

### 1 gallon = 4.55litres

16

## 1litre = ? Gallon = 1,000ml

### 1 litre = 0.22Gallons = 1,000ml

17

## 1 kg = ?lbs

### 1 kg = 2.2lbs

18

## 1lbs = ?kg

### 1lbs = 0.45kg

19

## What does a direct proportion graph look like?

### Top left to top right positive gradient

20

##
What are the five steps to work out the formula connecting y and x when:

Y is directly proportional to x

X = 30 Y = 45

###
Y {proportional} x

45 {proportional} 30

45 = k x 30

45/30 = k

K = 1.5

21

##
Y is directly proportional to x

K = 1.5

Find y when X = 40

###
K = 1.5 X

Y = 1.5 x 40

Y = 60

22