Answer: B) 50 Explanation: 15 girls are absent => b = 2(g-15)...... eqn...(1) 45 boys are absent => g - 15 = 5(b-45).....eqn...(2) => g = 5(b-45) + 15 => b = 2((5(b-45)+15)-15) => b = 2(5b - 225 + 15 - 15) => b = 2(5b-225) => b = 10b - 450 => 9b = 450 => b = 50 so from equation(2) g - 15 = 5(b - 45) => g - 15 = 5(50-45) => g - 15 = 5(5) => g = 25 + 15 => g = 40 Therefore, the number of boys = 50 and girls = 40

Answer: D) it is either homogenous or heterogenous Explanation: A mixture is the blending of two or more dissimilar substances.   Characteristics of a Mixture: 1. It has No formula. 2. It is an impure sustance 3. They can be mixed in any ratio. 4. The properties of the mixture are the properties of its constituents. 5. Constituents can e easily seperated by physical methods.eg: Heating, Drying, Crystallization, Distillation etc... 6. It is either homogenous or heterogenous.   A major characteristic of mixtures is that the materials do not chemically combine. Mixtures can be divided into those that are evenly distributed (homogeneous) and those that aren't (heterogeneous).

Answer: D) Crystallization Explanation: