Problem solving

 7.4 Problem Solving
 SITUATION 1

Puan Ayu prepared 12 cupcakes. 5 of the cupcakes are chocolate flavoured and the rest are pandan flavoured. If 2 chocolate cupcakes and 5 pandan cupcakes are eaten by her children, what is the ratio of the remaining chocolate cupcakes to the remaining pandan cupcakes?

SOLUTION:

 FLAVOUR Chocolate Pandan Number of cupcakes 5 $$12-5=7$$ Number of cupcakes eaten 2 5 Number of the remaining cupcakes $$5-2={\color{red}3}$$ $$7-5={\color{red}2}$$

The ratio of the remaining chocolate cupcakes to the remaining pandan cupcakes is 3:2.

 SITUATION 2

8 kaya buns and 12 red bean buns are repacked into 4 packets with the same number of kaya and red bean buns. What is the ratio of the number of kaya buns to the number of red bean buns in each packet?

SOLUTION:

• The number of kaya buns in each packet is $$8\div 4=2$$.
• The number of red bean buns in each packet is $$12\div 4 = 3$$.

The ratio of kaya buns to the number of red bean buns is 2 : 3.

 SITUATION 3

Muthu uses 7 cups of flour and 3 cups of milk to make the dough. His friend, Laili, wants to try the same recipe but she reduces a cup of flour and adds 2 cups of milk compared to Muthu's dough. What is the ratio of the number of cups of flour to the number of cups of milk used by Laili?

SOLUTION:

Find the ratio of the number of cups of flour to the number of cups of milk used by Laili.

• Flour used by Lili: 7 cups - 1 cup = 6 cups
• Milk used by Laili: 3 cups + 2 cups = 5 cups

The ratio of the number of cups of flour to the number of cups of milk used by Laili is 6 : 5.