Decimal P6 2010 SA2 Maha Bodhi P2 Q6

Mrs Gopal and Mrs Ari went to the supermarket. Both women decided to spend all their money on either apples or pears and they would not buy the same fruit.
If Mrs Gopal bought only pears, she would have 9 more fruit than Mrs Ari.
If she bought only apples, she would have 41 more fruit than Mrs Ari.
How much more money has Mrs Gopal than Mrs Ari?
 
 
40 : 60 = 2 : 3    Number bought   3 : 2 (inverse)
 
Number
G [          ][          ]
A [   ][   ][    ]<9>
 
2 u --> 3 p + 9
 
6 u --> 9 p + 3 x 9 = 9 p + 27
 
 
Number
G [          ][          ][          ]
A [   ][   ]<----- 41 ------>
 
3 u --> 2 p + 41
 
6 u --> 4 u + 2 x 41 = 4 p + 82
 
9 p + 27 --> 4 p + 82
 
5 p --> 82 - 27 = 55
 
1 p --> 55/5 = 11
 
3 p --> 3 x 11 = 33
 
2 u --> 33 + 9 = 42
 
 
42 x 0.60 = $25.20
 
33 x 0.40 = $13.20
 
25.2 - 13.20 = $12
 
It was $12


Alternatively
---------------

40 : 60 = 2 : 3   Number bought  3 : 2 (inverse)


Number


G [          ][          ]
A [   ][   ][   ]<9>




Number


G [          ][         ][          ]
A [   ][   ]<----- 41 ------>


5 u --> 5 p + 9 + 41 = 5 p + 50


5 u - 5 p --> 50


2 u - 2 p --> 2/5 x 50 = 20        Compare only number of pears bought


20 x 0.60 = $12


It was $12.

Area P6 2010 SA2 Maha Bodhi P2 Q7

10 / 2 = 5    Right-angled isosceles triangle(s)

1/2 x 10 x 5 = 25

25 + 133 = 158 cm2

It is 158 cm2.

Decimal P6 2010 SA2 Maha Bodhi P2 Q12

Talik was given some pocket money for recess. He realised that if he had spent $0.80 on each meal, he would have 8 meals fewer than if he had spent $0.60 per meal. Talik spent $0.60 on 8 meals and spent $0.80 on the remaining meals. How many meals did the money last him? [4 marks][Answer given: 26 meals]


8 x 0.60 = $4.80

$0.80 - 0.60 = $0.20

4.80/0.20 = 24 meals --- $0.80

24 x 0.80 = $19.20

19.20 - 4.80 = $14.40

14.40/0.80 = 18 meals

18 + 8 = 26 meals

It was 26 meals.