Question
The average height of each person in group 'C' having 25
people is 10 cm less than the average height of each person in group 'D' having 20 people. If the sum of the heights of all people in group 'C' is the same as that in group 'D', then what is the average height of a person in group 'D'?Solution
ATQ, Let the average height of a person in group 'D' = 'y' cm. Then, the average height of a person in group 'C' = (y - 10) cm. Total height of all people in group 'D' = 20 × y = '20y' cm. Total height of all people in group 'C' = 25 × (y - 10) = 25y - 250 cm. So, 25y - 250 = 20y. Or, 5y = 250. So, y = 250 / 5 = 50. Required average height = 50 cm.
The average age of 30 students in a class is 18 years. The average age of another 20 students is 22 years. Find the average age of all the 50 students t...
Average run scored by a batsman in 20 innings is 88. In next 6 innings, he scored runs with an average of ‘x’ so that his overall average increases ...
The average age of 12 boys in the group is 9 years. If 2 more boys join the group, the average is increased by 1 year. What is the average age (in years...
The total number of teachers in Department A and Department B together is 112. The number of teachers in Department A is 80% more...
The average of five even numbers is 68. If we replace two of these even numbers, 84 and 92, with a single even number X, the new average decreases by 4....
The mean of a set of 8 numbers is 80. If the average of the first four numbers and the last two numbers is 90 and 60, respectively, and the ratio of the...
In a company, the average age of 40 employees is 20 years. When the ages of two managers, one 'a' years old and the other 'a + 10' years old, are includ...
The average salary of department A with n employees is ₹40,000, and that of department B with (n+15) employees is ₹50,000. If the combined average ...
The average age of A and B is 17 years. If A is to be replaced by C, the average would be 16 years. The average age of C and A is 18 years. Find the age...
- The average of five numbers is 62. When three more numbers are included, the average increases by 6. Find the average of the numbers included.
Relevant for Exams:
