Directions: Find the wrong number in the following number series:

141, 156, 147, 162, 153, 165, 159

If $$ ({x+y\over z})=2$$ , then what is the value of $$ [{ {y\over {y-z}}}] +[{ {x\over {x-z}}}]$$.

A batsman scores 98 run in the 17^th match of his career. His average runs per match increased by 2.5. What is his average before the 17^th match?

Read the following graph carefully and answer the related questions-

Total number of students (in thousands) participating in comitative exam in various cities.

What is the ratio of number of students appearing tor competitive exam from city B to number of students appearing for competitive exam from city A? 

What is the height (in cm) of an equilateral triangle whose each side is 8 cm?

The average age of a man and his son is 55 years. The ratio of their ages is 7 : 4, respectively. What will be the ratio of their ages after 6 years?

The average salary, per head, of all the workers of an institution is 60. The average salary of 12 officers is 400; the average salary, per head, of the rest is 56. The total number of workers in the institution is -

The area of a triangle is 96 cm² and the ratio of its sides is 6 : 8 : 10. What is the perimeter of the triangle?