let number of passed candidates be
failed candidates =(100-X)
According to the question
X X +35(100-X)X10=100X30
The required number of students who passed the examination is 75.
Step-by-step explanation: Given that the average marks obtained by 100 candidates in an examination are 50.
The average marks of candidates who passed are 60 and that of the failed candidates are 20.
We are to find the number of candidates who passed the examination.
Let x represents the number of candidates who passed the examination and S be the sum of the marks scored by all the 100 students.
Then, the number of students who failed the examination = 100-x.
According to the given information, we can write
Sum of the marks scored by the students who passed is given by
sum of the marks scored by the students who passed is given by
Therefore, we get
Thus, the required number of students who passed the examination is 75.
So sum of all their mark is 50x100=5000
Let m be the no passed
Then 100-m be the no failed
So 60m + (100-m)20=5000
40m = 3000
m = 75
path is 10 planks wide
a footbridge is 5 feet wide and is built with wood planks that are 6 inches wide. how many planks wide is the path?
footbridge is 5ft wide
1ft = 12 inches
so footbridge width = 5 * 12 = 60 inches
width of a wooden plank = 6 inches
number of planks required to make a width of 60 inches = 60/6
so path is 10 planks wide