The figure shows a trapezium PQRS where RS = 17m and PS = 15m. If PT = 14m, and the area of trapezium is 196m2, Find the length
2 answers:
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First, find what percentage of students had 3 or more by adding up your known percents:
45% + 23 % + 21% + x% = 100%
x = 11%
Since you're given that 96 students had 2 or more, you add up the percentages of 2 and 3 or more:
11 + 21 = 32%
Now set up a proportion that relates it to the whole:
This will allow you to find the total number of students at the school.
Cross multiplying and solving for x results in 300 total students.
Question 1:
45% had one or more absences. 45% of 300 students is 135 students.
Question 2:
As we found before, 11% of students had three or more. 11% of 300 is 33 students.
45% + 23 % + 21% + x% = 100%
x = 11%
Since you're given that 96 students had 2 or more, you add up the percentages of 2 and 3 or more:
11 + 21 = 32%
Now set up a proportion that relates it to the whole:
This will allow you to find the total number of students at the school.
Cross multiplying and solving for x results in 300 total students.
Question 1:
45% had one or more absences. 45% of 300 students is 135 students.
Question 2:
As we found before, 11% of students had three or more. 11% of 300 is 33 students.
Because this is a fourth degree that will be tricky to factor as it is, we will do a u substitution. Let . We can now rewrite that polynomial in terms of u:
. Filling into the quadratic formula we have
. Simplifying down
and
or
. That means that u = 8 or u = -1. But don't forget that we let
, so we have to put x-squared back in for u. That gives us
which simplifies down to
. That also gives us
. When we take the square root of -1, we have to use the fact that -1 = i^2, so we sub that in to get
. All in all, your solutions are as follows:
which is choice b.