the average age of the class is 14.6years.the average age of boys is 12.4 years.the average age in girls is 16.2 years. the ratio of the number of boys to number of girls is?
Answers
Answer:
8:11
Step-by-step explanation:
Average = Sum of observations / No. of observations
Sum of observations = No.of observations * Average
Let
No. of boys = x
No. of girls = y
=> No. of boys and girls = class strength = x + y
Average age of boys = 12.4
=> Sum of ages of boys = 12.4x
Average age of girls = 16.2
=> Sum of ages of girls = 16.2y
Average age of boys and girls (class) = 14.6
=>Sum of ages of class = 14.6(x + y)
Clearly,
Sum of ages of class = Sum of ages of boys + Sum of ages of girls
=> 14.6(x + y) = 12.4x + 16.2y
=> 14.6x + 14.6y = 12.4x + 16.2y
=> 14.6x - 12.4x = 16.2y - 14.6y
=> 2.2x = 1.6y
=> x/y = 1.6/2.2
=> x/y = 16/22
=> x/y = 8/11
=> x:y = 8:11
Answer: Ratio of boys to girls is 8:11
Answer:
8:11
Step-by-step explanation:
No. of boys =m,→=m,→ average of boys →x=12.4→x=12.4
No. of girls =n→=n→ average girls →y=16.2→y=16.2
mx+nym+n=14.6mx+nym+n=14.6
12.4m+16.2n=14.6m+14.6n12.4m+16.2n=14.6m+14.6n
2.2m=1.6n2.2m=1.6n
mn=1622=811mn=1622=811
m:n=8:11m:n=8:11