Question

In a class 30% of the students are high achievers 40% of the students are average achievers and the 15 students are low achievers how many total students are in the class​

Answer 1

Step-by-step explanation:

40 +30+x=100

x=30

but x is 15 students

therefore 30%= is also equal to 15 students

40% =20 students

Total 20+15+15=50 students

Answer 2

Given

30% of the students are high achievers ,40% of the students are average achievers and 15 students are low achievers.

To Find

Total number of students in the class

Answer

Let us assume that the total number of students in the class be 'x'.

According to the question:-

30% of the students are high achievers =30/100 of x=3/10x

40% of the students are average achievers =40% of x =40/100x=2/5x

Now add them all

Total number of students = Number of high achievers students + number of average achievers students+number of low achievers

=>$\sf\dfrac{3}{10} x + \dfrac{2}{5} x + 15=x$

x= LCM of 10,5 & 15/1 is 10

=>$\sf \dfrac{3x + 4x + 150}{150} = x$

=>$\sf \dfrac{7x + 150}{10} = x$

Now,cross multiply

=>10x=7x+150

=>10x-7x=150

=>3x=150

=>x=150/3

x=50

hence ,the total number of students in the class is 50.

Check

30% of students are high achievers=30%×50=30/100×50=150/10=15

40% of the students are average achievers=40/100×50=200/10=20

and 15 students are low achievers

Total students=15+20+15=30+20=50