Question

the average score of boys in the examination of a school is 71 and that of girl is 73. the average score of the boys and girls is 71.8. find the ratio of number of boys to thr number of girls who appeared in tge examination

Answer 1

Answer:

3:2

Step-by-step explanation:

let x be the number of boys who took the exam......

let y be the number of girls who took exam .........

total number of student who took the exam is x + y

therefore,

sum of scores of boys = 71x

sum of scores of girls = 73y

now,

the sum of scores of all students = 71x + 73y

the average of all student is 71.8

the average of all students = the sum of scores of all students /total number of students

71.8 = 71x = 73y / x+y

71.8 ( x+y ) = 71x + 73y

71.8x + 71.8y=71x = 73y

71.8x + 71x = 71.8y - 73y

0.8x = 1.2y

x/y = 1.2 /0.8

x/y = 12/8

x/y = 3/2

therefore, the ratio number of boys to the number of girls is 3:2