Please wait...

Problem on Average Test 57
Result
Problem on Average Test 57
  • /

    Score
  • -

    Rank
Time Taken: -
  • Question 1/5
    1 / -0.25

    Average of a, b and c is 9. Average of b and c is 10. What is the value of a?
    Solutions

    Average of a, b and c is 9.

    Sum of a, b and c = 9×3 = 27

    Average of b and c is 10.

    Sum of b and c = 10×2 = 20

    Hence, a = 27 – 20 = 7

  • Question 2/5
    1 / -0.25

    The average of four numbers is 20. If the average of the first two numbers is 15, then what is the average of the last two numbers?
    Solutions

    Let the four numbers are a, b, c, and d.

    It is given, (a+b+c+d)/4 =20; (1)

    (a+b+c+d) = 4×20 = 80;

    Also, (a+b)/2 = 15 (a+b)= 30; (2)

    subtract (2) from (1);

    (a+b+c+d) - (a+b) = 80-30;

    (c+d) = 50;

    The required average of the last two number= 50/2= 25

  • Question 3/5
    1 / -0.25

    The average weight of 18 boys in a group is 35 kg. If four new boys of weights 20 kg, 22 kg, 26 kg and 28 kg are added to the group, then what is the average weight of the newly formed group?
    Solutions

    Formula: Average = (Sum of observations)/(Total no. of observations)

    Sum of weight of all 18 boys = 18 × 35 = 630 Kg.

    Average of all 22 boys = (630+20+22+26+28)/22 = 33 years

  • Question 4/5
    1 / -0.25

    The average age of 12 boys is 15 years and the average age of 18 girls is 12 years. What is the combined average age of the boys and girls, taken together?
    Solutions

    Average age of 12 boys = 15 years

    Sum of age = 12 × 15 = 180 years

    Average age of 18 girls = 12 years.

    Sum of ages of 18 girls = 12 × 18 = 216 years

    Average of all Girls and Boys = (180 + 216)/30 = 13.2 years

  • Question 5/5
    1 / -0.25

    There are 96 students in a class, out of which the number of girls is 40% more than that of the boys. The average score in mathematics of the boys is 40% more than the average score of girls. If the average score in mathematics of all the students is 63, then what is the average score of the girls in mathematics?
    Solutions

    Total number of students = 96

    Let the number of boys be denoted by B and girls by G

    G + B = 96

    Given that number of girls is 40% more than that of number of boys.

    G = B + 40%B =

    Substituting the value in above equation :

    B +

    B = 40 and G = 56

    Let average marks of Boys = x

    Total marks scored by 40 boys = 40x

    And average marks of girls = y

    Total marks scored by 56 girls = 56y

    x = y +

    According to question :

    112y = 63 × 96

    y = 6048/112 = 54

User Profile
-

Correct (-)

Wrong (-)

Skipped (-)


  • 1
  • 2
  • 3
  • 4
  • 5
Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Click on Allow to receive notifications
×
Open Now