a student has answered 82% of the questions correctly in the examination. He made mistakes in 9 questions Calculate the toltal n
1 answer:
Answer:
There is a total 50 questions.
Step-by-step explanation:
Let x = total questions in the exam
Since 82% of the test was scored correctly, that means 18% of the student's exam was scored incorrectly.
With this information we can write:
(Given that the student made 9 mistakes)
(divide 18% on both sides)
∴ There was a total of 50 questions in the examination.
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Answer
Find out the how high up the wall does the ladder reach .
To proof
let us assume that the height of the wall be x .
As given
A 25-foot long ladder is propped against a wall at an angle of 18° .
as shown in the diagram given below
By using the trignometric identity
now
Base = wall height = x
Hypotenuse = 25 foot
Put in the trignometric identity
x = 23.8 foot ( approx)
Therefore the height of the ladder be 23.8 foot ( approx) .
<span>In triangle WXZ,
Line WY is an altitude (as shown in the attached picture)
Now, it is given that:
</span><span>If ΔYWZ ~ ΔYXW
</span>∠WXY = ∠WZY
<span>
Then, we can also conclude
</span>∠WYX = ∠WYZ = 90°....(1) (because WY is the altitude)
Now, in any triangle, the sum of all the three angles is 180.
In triangle, WXY, ∠WYX = 90° (From 1)
Therefore, WXY + XWY = 90°
Similarly, in WZY.
Hence, we conclude that XWZ is a right angle.
Line WY is an altitude (as shown in the attached picture)
Now, it is given that:
</span><span>If ΔYWZ ~ ΔYXW
</span>∠WXY = ∠WZY
<span>
Then, we can also conclude
</span>∠WYX = ∠WYZ = 90°....(1) (because WY is the altitude)
Now, in any triangle, the sum of all the three angles is 180.
In triangle, WXY, ∠WYX = 90° (From 1)
Therefore, WXY + XWY = 90°
Similarly, in WZY.
Hence, we conclude that XWZ is a right angle.