Question

75% of student answered 1st question correctly and 55% of student answered 2nd question correctly and 20% of student answered both the questions wrong. what is the percentage of students in which both the questions would be answered correctly???
i need explanation

Answer 1

For the 1st question, 75% of the total students answered it correctly. Another way of writing that is (75/100)
For the 2nd question, 55% of the total students answered it correctly. Another way of writing that is (55/100)
Now 20% of the total student got both questions wrong. Another way of writing that is (20/100)
Now think outside the box, or think logically.

We want to find how many students got both of it right.

So to do it, we need an equation.

Answer 2

The total students score = (First + Second - Both + Neihther)
Make sense so far?

Answer 3

I can explain it more if you want.

Answer 4

i dont know it is correct r not
i draw the pie chart and i separated into 4 parts, each 25% (ie.,consider 25 students), 3 parts is filled with 75% and so on for the rest two.....
so i think 55% im not sure man.......

Answer 5

is this incorrect means explain me....

Answer 6

I have to go soon, but I'll explain it. This is going to be a little bit hard to explain, but I hope you understand it.

So 75% of the total students got the 1st question correct.
55% of the total students got the 2nd question correct

Now remember, we are asking what is the percent in which both students got it right.

So if we add 75% + 55%, we would get 130%. Though how is this possible? Just wait. ;)
So pretend that there's 100 students in total.

75/100 got the 1st question right.
And 55/100 got the 2nd question right.

But 75 + 55 = 130. How is this possible? Well this mean that some people got both question right. So does that mean that the remaining 30% is the total amount of students who got it right. Not quite.

Remember, 20% of the total students failed both questions!

So remember the equation I gave you?
"The total students score(100%) = (First + Second - Both + Neither) "
Does it make sense a little bit?

Answer 7

It's not 55%.

Answer 8

your explanation is good man but im too poor in maths still i cant get...can you explain me with the answer

Answer 9

So "The total students score(100%) = (First + Second - Both + Neither)" in REAL equation form would look like: \[\large \large 100(percent) = 75(percent) + 55(percent) - X (percent) + Neither(Percent)\]

Answer 10

Don't worry. This type of problem required a little bit of complex thinking.

Answer 11

thank you.....50% .....why cant we try it in pie chart r venn diagram?????.....

Answer 12

We can't add another section on who got both question right because if we did, then it would be similar to the 75% and the 55% sections.
I hope this help!