Question

out of a class of 45 student, 5 absent, 30% of the remaining had failed to do the homework . find the number of students who did the homework?

Answer 1

45-5 = 40..

30% =

$30 \div 100 \times 40$

= 12

Remaining 40-12

28 students had done the homework...

Answer 2

Answer :-

28 students did their Homework

Explaination :-

Given :-

Total strength of the class = 45

Absent students = 5

Total students present : 45 - 5 = 40 students

Percentage of students failed to do the homework = 30%

To find :-

Students did their homework

Solution :-

First we have to find the students who didn't did their homework.

$= > 30\% \: of \: 40$

$= > \frac{30}{100} \times 40$

Reduce them

$= > \frac{30}{10} \times 4$

$= > 3 \times 4$

$= > 12$

$\small{\green{\boxed{\green{\boxed{\red{\textsf{Students who didn't do the H.W = 12}}}}}}}$

$\textbf{Students\: who\: did\:their\:H.W}$

$= > 40 - 12$

$= > 28$

$\small{\green{\boxed{\green{\boxed{\red{\textsf{Students did their H.W = 28}}}}}}}$

$\textbf{\large{METHOD\:2}}$

=> PERCENTAGE of students did their H.W = 100% - 30% = 70%

=> 70 % of 40

=> 70/100 × 40

=> Reduce them

=> 7 × 4

=> 28

$\small{\green{\boxed{\green{\boxed{\red{\textsf{Students did their H.W = 28}}}}}}}$

$\therefore$ 28 students did their Homework.