Mr. Bobby bought 50 shares at $60, and 2 months later purchased 25 shares a $56.at what price should he purchase 25 additional shares in order to have an average price $58 per share?

Question

The average age of a family of 6 members is 25 years. The average of the family after a 45 years old members leaves is?
In a course a students final exam is weighted twice as heavily as his midterm exam.If a student receives a score of 84 on his final exam and 90 on his midterm exam ,what is the average for the course?

Answer 1

#1: If the price is x, then we must have

50*60 + 25*56 + 25x = 58(50+25+25)

#2: (6*25-45)/5

#3: (90+2*84)/3