Question

5. In a school there are 2000 students. On January
2nd, all the students were present in the school
except 4% of the boys and on January 3rd, all
the students are present in the school except
28/3% of the girls, but in both the days number
of students present in the schools were same.
The number of girls in the school is?​

Answer 1

Step-by-step explanation:

Let the no. of girls be Y

and no. of boys be X.

So, total no. students in school = X + Y

We know that,

no. of students in school = 2000

So,

X + Y = 2000 ---------------------------(1)

Now,

On 2nd January,

4% boys were absent.

So, no. of boys present = X – 4% of X

= X – (4÷100)×X

=X – X/25

= 24X/25

So,

Total no. of students present = 24X/25 + Y

Now,

On 3rd January,

28/3% girls were absent.

So, no. of girls present = Y – 28/3% of Y

= Y – (28/300)×Y

= Y – 28Y/300

= 272Y/300

So,

Total no. of students present = X + 272Y/300

According to the question,

24X/25 + Y = X + 272Y/300

On solving further,

7Y = 3X

X = 7Y/3 ---------------------------------------(2)

On substituting the value of X in equation 1,

7Y/3 + Y = 2000

10Y/3 = 2000

10Y = 6000

Y = 600

So,

from equation 1,

X = 2000 – Y

X = 2000 – 600

X = 1400

So,

no. of girls in school = 600