Describe the given ratio in words 24 27 of the planet's surface is covered with water.

Given ratio 24 27 a : b is written as a b Simplest form of a b means cancel out the common factors of both a and b in both numerator and denominator. Simplest ratio of 24 27 is 24 27 = 8 × 3 9 × 3 = 8 9 Therefore, Eight-ninth of the planet surface is covered with water

Find x and y in the relation: 3 x = 15 20 = 45 y

Given, 3 x = 15 20 = 45 y Equate 3 x = 15 20 If two ratios are in proportion then their Product of mean = Product of extreme ⟹ 3 × 20 = x × 15 ⟹ x = 3 × 20 15 ⟹ x = 60 15 ⟹ x = 4 Equate 15 20 = 45 y ⟹ 15 × y = 20 × 45 ⟹ y = 20 × 45 15 ⟹ y = 20 × 3 ⟹ y = 60

Find a , b , c and d in the relation : 1 7 = 2 a = b 42 = 4 c = d 84

If two ratios are in proportion then their Product of mean = Product of extreme Equate 1 7 = 2 a ⟹ a × 1 = 2 × 7 ⟹ a = 14 Equate 1 7 = b 42 ⟹ b = 42 7 ⟹ b = 6 Equate 1 7 = 4 c ⟹ c = 4 × 7 ⟹ c = 28 Equate 1 7 = d 48 ⟹ d = 84 7 ⟹ d = 12 Therefore, a = 14 , b = 6 , c = 28 , d = 12