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CHAPTER AT A GLANCE
Proportional Reasoning-1
•Unit: Ratio and Proportion
•Board weightage: Ratio, proportion and the Rule of Three give regular 1-mark, 2-mark and 3-mark questions, including word problems (please check the latest sample paper)
•Key ideas from the textbook: change by the same factor, ratio in simplest form, proportion (a : b :: c : d), cross multiplication, the Rule of Three (Trairāśika), dividing a quantity in a ratio, unit conversions
•Most scoring part: finding the fourth term of a proportion and sharing a quantity in a given ratio
•Time to revise: about 60 minutes
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