Fatimah and Hairu enjoy Congkak game part 22 (Math Question)

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The blog postings are about the Singapore Math. The readers can learn from the postings about Solving Singapore Primary School Mathematics. The blog presenting the Math Concept, Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can aquire the skills of dealing with Math Modeling, Problem Sum from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper primary school math question on Percentage, Ratio and Problem sum.

Read the posting on Fatimah and Hairu play Congkak to know about Congkak game.

Read also the posting on Sarin learns Average Number, Percentage and Charting in school (Math Concept) to know about Pie Chart.

You should also read the posting on to understand mathematics concept of Ratio.

Challenge yourself with the question before look for the given solution‼!

Upper primary school mathematics question UPQ279

Fatimah uses some green, red and blue marbles in the Congkak game. She has 25% more green marbles than red marbles, and 20% less blue marbles than green and red marbles.

(a) What is the ratio of red marbles to green marbles to blue marbles?

(b) If there are 11 more blue marbles than green marbles, how many red and green marbles are there?

Solution:

Draw the ratio model and subdivided to 10 divisions per blocks.

Green and red marbles are 90 units

Blue marbles = 90 × 80% = 72 units

The ratio of marbles, R : G : B = 40 : 50 : 72 = 20 : 25 : 36

There are 11 more blue marbles than green marbles

(36 – 25) = 11 units = 11

1 unit = 1 marble

The number of red and green marbles = 20 + 25 = 45

Alternative solution:

25% more green marbles than red marbles

The ratio of marbles

G : R = 1.25 : 1 = 5 : 4

G : R : (G + R) = 5 : 4 : 9 = 25 : 20 : 45

20% less blue marbles than green and red marbles

B : (R + G ) = 0.8 : 1 = 4 : 5 = 36 : 45

There are same amount of Green and Red marbles.

The ratio of marbles,

R : G : B  = 20 : 25 : 36

11 units = 11

1 unit = 1 marble

The red and green marbles = 20 + 25 = 45