Question
The average age of (x + 4) students of a class is 18 years.
If the 54 years old class teacher is also included then average age of the class gets increased by two years. Find x% of 300.Solution
Total age of students = 18(x + 4) years
According to question,
[18(x + 4) + 54] = (18 + 2)(x + 4 + 1)
18x + 72 + 54 = 20x + 100
20x – 18x = 126 – 100
x = 13
So, 13% of 300 = 39
5 positive numbers are written on a piece of paper. Sum of first 3 numbers is 55 and ratio of the 4th and the 5th number is 2:3. If difference between t...
The average salary of all males and females in an office is Rs.16000 and the total number of females in the office is 16. If the average salaries of mal...
The batting average for 27 innings of a cricket player is 48 runs. His highest score in an innings exceeds his lowest score by 157 runs. If these two in...
The average number of taxis of three colours (black, white and yellow) in a taxi stand is 160. The number of black taxis is 65 more than that of yellow ...
The average of five consecutive odd numbers is 45. What is the average of the first three numbers among them?
2040, 600, 240, 150, ?, 121.875
Of the four numbers, whose average is 75, the first is one-fourth of the sum of the last three. The first number is
- A student scored an average of 81 marks in his first 30 tests. In the next 10 tests, his average score was ‘x’ marks, and his overall average rose to 8...
The average age of three children is 32 years. If their ages are in the ratio 3:6:7. Find the age of the youngest child.
In an examination, the average marks obtained by the students is 75. After correcting the quantitative mistakes, the average of 100 students is reduced...
