Question

Find the total output of a coal mine if after 14% wastage, the net output is 68,400 quintals
.
In a class of 740 students, 10% students secured first division, 15% students secured seco
and 10% were just passed. What per cent of students failed?
obtained by​

Answer 1

Answer:

A) Let the total output be x quintals.

and after 14% the net output is 68,400 quintals.

Total output - Net output = Wasted output

$= > x - 68400 = 14\% \: of \: total \: output$

$= > x - 68400 = \frac{14}{100} \times x$

$= > x - \frac{14x}{100} = 68400$

$= > \frac{100x - 14x}{100} = 68400$

$= > 86x = 64800 \times 100$

$= > x = \frac{68400 \times 100}{86}$

$= > x = 79534.88 \: quintals$

so, the total output is 79534.88 quintals.

B) Number of students who secured first div

$= \frac{10}{100} \times 740$

$= 74 \: students$

=> Number of students who secured 2nd div,

$= \frac{15}{100} \times 740$

$= 111 \: students$

=> number of students who just passed

$= \frac{10}{100} \times 740$

$= 74 \: students$

So remaining students who failed =

$740 - (74 + 74 + 111) \\ = 481$

So, percentage of failed students

$= \frac{481}{740} \times 100$

$= 65\%$

So, percentage of students failed is 65%