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Yakvenalex [24]
3 years ago
9

In a test, +3 marks are given for every correct answer and -1 are given for every incorrect answer (i) Sona scored +20 marks tho

ugh she got 10 correct answers. How many incorrect answers has she attempted??
Mathematics
1 answer:
e-lub [12.9K]3 years ago
4 0

Answer:

10 incorrect answers

Step-by-step explanation:

Correct answer = +3

Incorrect answer = - 1

Mark scored = 20

Number of correct answers = 10

Let:

Incorrect answers = y

Hence, we can fashion out the expression for total score :

(Number of correct answers * score per Correct answer + number of incorrect * score per incorrect) = total score

(10 * 3) + (y * - 1) = 20

30 - y = 20

-y = 20 - 30

-y = - 10

y = 10

10 incorrect answers

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A cone has a slant length of 5 and a diameter of 4. What is the volume of the cone? Use π ≈ 3.14.
Olegator [25]

Answer:

V = 19.19 cubic units

None of the options are correct.

Step-by-step explanation:

Volume of a cone is given as;

V = ⅓πr²h

Now, we are given;

diameter = 4 units

Thus radius;r = diameter/2 = 4/2 = 2 units

I have attached an image to show the diagram of the cone.

Now, to find the height (h), we know the radius(r) and we know the slant length(l) . So we can use Pythagoras theorem to find the height.

From Pythagoras theorem;

r² + h² = l²

Where l is the hypotenuse or the slant side while "r" is the radius of the cone while the height will be "h"

Thus;

2² + h² = 5²

h² = 5² - 2²

h² = 25 - 4

h² = 21

h = √21

h = 4.5826 units

So height (h) = 4.5826 units

Volume of cone;V = ⅓πr²h

We are told that π = 3.14

Thus;

V = ⅓ x 3.14 x 2² x 4.5826

V = 19.19 cubic units

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Answer:

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