A. 15
B. 9
C. 18
D. 21
3x + 5x + 7x = 45
x =3
3x = 9
Related Mcqs:
- The present average age of a family of five members is 26 years. If the present age of the youngest member in the family is ten years, then what was the average age of the family at the time of the birth of the youngest member ? (Assume no death occurred in the family since the birth of the youngest).
A. 18 years
B. 14 years
C. 20 years
D. 16 years - Three years ago the average age of a family of six members was 19 years. A boy have been born, the average age of the family is the same today. What is the age of the boy?
A. 1 year
B. 1.5 years
C. 2 years
D. 2.5 years - The average age of seven persons sitting in a row facing east is 28 years. If the average age of the first three persons is 21 years and the average age of the last three persons is 34 years, then find the age of the person sitting in the middle of the row?
A. 30 Years
B. 31 years
C. 26 years
D. 33 years - The average age of students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years. The ration of the number of boys to the number of girls in the class is___________?
A. 1:2
B. 2:3
C. 3:4
D. 3:5 - Five years ago the average of the ages of A and B was 40 years and now the average of the ages of B and C is 48 years. What will be the age of the B ten years hence?
A. 55 years
B. 56 years
C. 58 years
D. Data inadequate - The average height of 35 boys in a class was calculated as 180cm. It has later found that the height of one of the boys in the class was wrongly written as 166 cm whereas his actual height was 106 cm. Find the actual average height of the boys in the class (Round off your answer to two decimal places)?
A. 179.29 cm
B. 178.29 cm
C. 179.38 cm
D. 178.39 cm - The average weight of 16 boys in a class is 50.25 kg and that of the remaining 8 boys is 45.15 kg. Find the average weights of all the boys in the class.
A. 47.55 kg
B. 48 kg
C. 48.55 kg
D. 49.25 kg - The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average of the team?
A. 23 years
B. 24 years
C. 25 years
D. None of these - The average weight of a group of boys is 30 kg. After a boy of weight 35 kg joins the group, the average weight of the group goes up by 1 kg. Find the number of boys in the group originally?
A. 4
B. 5
C. 6
D. 7 - The average age of M boys is ‘b’ years and of ‘n’ girls ‘c’ years. The average age of all together is_________?
A. (mb – nc)/ (m + n) years
B. (mb + nc)/ (m – n) years
C. (mb + nc)/ (m + n) years
D. (mb – nc)/ (m – n) years
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