# Math Questions With Answers (4)

A set of comprehensive math questions are presented. Answers to these questions are also provided and are located at the lower part of the page.

 Questions 1: How much water should be added to 20 ounces of a 20% acid solution to reduce it to a 10% solution? Questions 2: Solve for C the following equation: B = 2 B D + 2 C E + 2 C L Questions 3: Thomas can paint the house in 6 days, while it takes Joe 12 days to paint the same house. How long would it take Thomas and Joe, working together, to paint the house? Questions 4: Solve the following system of equations 3x - 4y = 25 -2x + y = -10 Questions 5: An airliner can make a 3,000 mile trip with tailwind (wind in the same direction as the airliner) in 4 hours and make the return trip against the wind (with the same speed) in 4 hours 48 minutes (4.8 hours). Find the ground speed of the airliner. Questions 6: Write as a single interval if possible: (-9 , 2) U (1 , 30) Questions 7: Solve the equation: |5x - 2| - 2 = 6 Questions 8: Solve the inequality: |4x + 6| < 30 Questions 9: Solve the inequality: |4x + 5| - 5 > 6 Questions 10: Solve the inequality: SQRT (3x - 2)2 < 5 Questions 11: Solve the equation: |-2x + 5| = 2x - 5 Questions 12: Solve the equation: |4x - 2| = 8x - 12 Questions 13: Evaluate and write in standard form: (4 - 2i)(-3 + 3i), where i2 = -1. Questions 14: Evaluate and write in standard form: (2 - 3i) / (2 - 2i), where i2 = -1. Questions 15: Evaluate and write in standard form: (-3 + 2i)2 - 3(3 - i)(-2 + 2i), where i2 = -1. Questions 16: Solve the equation: -(x - 2)2 - 2 = 7 Questions 17: Solve the equation: (-x + 3)2 - 12 = 8 Questions 18: Solve the equation: 3 + 30/x2 = -21/x Questions 19: Solve the equation: -x / (x2 + 2x - 3) + 5 / (x + 3) = 1 Questions 20: The sum of a number and its reciprocal is 82 / 9. Find the number. ANSWERS TO ABOVE QUESTIONS 1) 20 ounces 2) C = B(1 - 2D) / (2E + 2L) 3) 4 days 4) (3 , -4) 5) 687.5 miles/hour 6) (-9 , 30) 7) x = 2 , x = - 6 / 5 8) -9 < x < 6 9) (- infinity , -4) U (3/2 , + infinity) 10) (-1 , 7/3) 11) [5/2 , + infinity) 12) x = 5/2 13) -6 + 18 i 14) 5/4 - i / 4 15) 17 - 36 i 16) x = 2 + 3 i , x = 2 - 3 i 17) x = 3 + 2 SQRT(5) , x = 3 - 2 SQRT(5) 18) x = -2 , x = -5 19) x = 1 + i , x = 1 - i 20) Two possible solutions: x = 9 and x = 1 / 9 More math questions and problems with detailed solutions in this site.