Question

In an examination 80%of the total candidates passed in english and 70%in maths while 20%failed in both. If total no.of candidates failed is 450,find the total number of candidates ​

Answer 1

Student Passed in English =80%

Students failed in English=100%−80%=20%

Students passed in Maths =70%

Students failed in Maths =100%−70%=30%

Students failed in both =10%

Total failed students = Failed in English + failed in Math − Common

Total fail students =20%+30%−10%=40%

If 40% failed then 60% will be passed.

Let total students be x.

Hence, 60% of x=144

⇒

100

60

×x=144

⇒x=

60

144×100

⇒x=240

Answer 2

Answer:

Step-by-step explanation:

Failed Students in English = 100% - 80% =  20%

Failed Students in Maths   = 100% - 70 % =  30%

Failed Students =(Failed students in English + Failed students in Maths) - Both Failed

Then, Total Failed = (20% + 30%) - 20%

                                = 30 %

Total Students = 100%

         Failed       = 30%

 

30 % = 450

100%= x    

100/ 30 * 450 = 1500