In a class the respective ratio between the number of boys and the numbers of girls is 3:1. atest was conducted where in the average socre of the boys was 73 while that of the entire class was 71. What was the average score of the girls
Answers
boys to girls ratio = 3:1, total boys and girls = 1+3 = 4
average score of boys = 73
average score of whole class = 71
average score of girls = 71*4 - 73*3 = 284 - 219 = 65
65 is the average score of girls
B's investment in 11 months = 4500 * 11 = 49500
Profit ratio = A:B
27500 : 49500
5:9
Difference of their profits = 9-5 = 4
And share of 4 = 4800
Share of 1 = 4800/4 = 1200
annual profit earned = 1200*(5+9) = 16800
Answer:
The average score of girls is 65.
Step-by-step explanation:
Since, the respective ratio between the number of boys and the numbers of girls is 3:1.
Let, the number of boys = 3x,
And, the number of girls = x,
Where x is any number.
Here, the average score of the boys was 73,
Total sum of the score of boys = 73 × 3x = 219x ( Because, Sum = Average × number of observations )
Now, let y be the average score of girls,
Total sum of the score of girls = y x,
Total sum of scores of boys and girls = 219 x + yx
Since, the average score of entire class = 71,
⇒ The total sum of scores of boys and girls = 71(x+3x) = 284 x
⇒ 219 x + yx = 284 x
y = 284 - 219 = 65.
Hence, the average score of girls is 65.