70% of students answered question A correctly, 55% of students answered question B correctly, 20% of students answered neither question correctly. What is the percentage of students answered both question A and B correctly?

70% of students answered question A correctly, 55% of students answered question B correctly, 20% of students answered neither question correctly. What is the percentage of students answered both question A and B correctly?

70% of students answered question A correctly, 55% of students answered question B correctly, 20% of students answered neither question correctly. What is the percentage of students answered both question A and B correctly?

45%

explanation:

Let the total number of students be 100 and the no. of students who answered both the questions correctly be x.

therefore no. of students who answered only A correctly is (70 - x)
and the no. of students who answered only B correctly is (55 - x)

70% of students answered question A correctly, 55% of students answered question B correctly, 20% of students answered neither question correctly. What is the percentage of students answered both question A and B correctly?

since 20% didnot answer correctly so that means only 80% are doing atleast one right

Q) In TestFunda , out of every 7 members posting on Verbal forums 3 post on quant forum as well. For every member posting on atleast one of these forums, there are 3 members who post on neither. If 10% of the members post only on verbal forum , the percentage of members who post on only quant forum is

1) 17.5% 2) 23.33% 3) 7.5% 4) None of these 5) Cannot be determined

Q) In TestFunda , out of every 7 members posting on Verbal forums 3 post on quant forum as well. For every member posting on atleast one of these forums, there are 3 members who post on neither. If 10% of the members post only on verbal forum , the percentage of members who post on only quant forum is

1) 17.5% 2) 23.33% 3) 7.5% 4) None of these 5) Cannot be determined

Q) In TestFunda , out of every 7 members posting on Verbal forums 3 post on quant forum as well. For every member posting on atleast one of these forums, there are 3 members who post on neither. If 10% of the members post only on verbal forum , the percentage of members who post on only quant forum is

1) 17.5% 2) 23.33% 3) 7.5% 4) None of these 5) Cannot be determined

Can sum1 plz tell me which type of sum is this? Which formula is applicable? Is it based on percentages?

Can sum1 plz tell me which type of sum is this? Which formula is applicable? Is it based on percentages?

Originally Posted by YadavAbhay

Like ShipraKaushik sum1 tell me also that which formula is used? What type is this sum? I cant got it.

Hi shipra and abhay

This is a basic sum based on the concept of sets...and can be solved by the method above or by using venn diagrams...just revise your concepts on sets and then you can easily solve such questions

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