Question

12. Find the total number of students. Also, find the number of students who passed, if 70% of total
students passed in an examination and 270 students failed.
​

Answer 1

Given :-

● 70% of total students passed in an examination.

● 270 of students failed.

To Find :-

● Total number of students.

● Number of students who passed.

Solution :-

● Let the total number of students be n.

${\bf\large{→\: \frac{70}{100} \times n + 270 = n }}$

${\bf\large{→\: \frac{70n}{100} + \frac{270}{1} = n }}$

${\bf\large{→\: \frac{70n + 27000}{100} = n }}$

${\bf\large{→\: {70n + 27000} = 100n}}$

${\bf\large{→\: {27000} = 100n - 70n}}$

${\bf\large{→\: {27000} = 30n}}$

${\bf\large{→\: \frac{27000}{30} = n}}$

${\bf\large\red{→\: 900 = n}}$

● Number of students passed :-

${\bf\large{→\: \frac{70}{100} \times 900}}$

${\bf\large{→\: \frac{70}{1} \times 9}}$

${\bf\large\red{ →\: }}$${\boxed{{\bf\red{∴630}}}}$

● Hence, 630 students passed.