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Last month's solutions

Solutions: A:

B:


Solution: Let x = hours working as a tutor and y = hours working as a lifeguard. x + y = 20, y = 20 – x, and therefore: 12x + 9.5y = 220 x = 12 and y = 20 – x = 20 – 12 = 8 

Solution: Triangles ADB and CDB are congruent to each other because since they are both 30°60°90° triangles and share the side BD. In triangle ADB, side AD is opposite to the angle 30° and therefore, the length AD is half the length of hypotenuse AB. Since the triangles are congruent, AB = BC = 12. So the length of AD = 12/2 = 6. 