English

The total age of 23 boys and 32 girls is 573 years while that of 32 boys and 23 girls is 582 years. Find the average age of a boy and a girl respectively. -

Advertisements
Advertisements

Question

The total age of 23 boys and 32 girls is 573 years while that of 32 boys and 23 girls is 582 years. Find the average age of a boy and a girl respectively.

Options

  • 10, 11

  • 12, 14

  • 11, 10

  • None of these

MCQ

Solution

11, 10

Explanation:

Let average age of a boy = x and a girl = y

23x + 32y = 573

32x + 23y = 582

Here the coefficients of x and y are interchanged, in such cases a faster method of solving the equation is by adding and subtracting the equations.

Adding 55x + 55y = 1155

x + y = 21  .....(i)

Subtracting 9y – 9x = – 9

x – y = 1  ......(ii)

From (i) and (ii)

2x = 22, x = 11, y = 10

shaalaa.com
Algebra (Entrance Exam)
  Is there an error in this question or solution?
Advertisements
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×