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3 years ago

Sally was standing 30 feet from a tree. The angle of

Mathematics

1 answer:

QveST [7]3 years ago

5 0

Answer: The tree was 27 feet tall

Step-by-step Explanation: First of all Sally was standing 30 feet away from the tree and she looks up at an angle of elevation of 38 degrees to the top of the tree. With this bit of information we can determine that a right angled triangle has been formed with the reference angle as 38 degrees, the side facing it as h (the height of the tree) and the adjacent side as 30. We shall apply the trigonometric ratio as follows;

Tan 38 = opposite/adjacent

Tan 38 = h/30

0.7813 = h/30

0.7813 x 30 = h

23.4 = h

We remember at this point that Sally’s eyes were 4 feet above the ground. What we have just calculated is the height of the tree from “4 feet above the ground” (where her eyes were). Hence the actual height of the tree is calculated as 23.4 plus 4 which gives us 27.4

Therefore the tree was 27 feet tall (approximately to the nearest foot)

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Andrea is at the grocery store buying fruit for a smoothie stand. She needs 7 boxes of raspberries for every 5 bunches of banana

Degger [83]

Answer:

The greatest number of bunches of bananas that Andrea can buy is 15 and the greatest number of boxes of raspberries that Andrea can buy is 21 to maintain the ratio 7:5

Step-by-step explanation:

Let

x ---->the greatest number of boxes of raspberries that Andrea can buy

y ---->the greatest number of bunches of bananas that Andrea can buy

we know that

$100\%+8\%=106\%=108/100=1.08$ ---> sales tax

$\frac{x}{y} =\frac{7}{5}$

$x=\frac{7}{5}y$ ----> equation A

$1.08[2.50x+3.00y]\leq 135$ ----> inequality B

substitute equation A in the inequality B

$1.08[2.50(\frac{7}{5}y)+3.00y]\leq 135$

solve for y

Multiply by 5 both sides to remove the fraction

$18.9y+16.2y\leq 675$

$35.1y\leq 675$

$y\leq 19.23$

The maximum value of y is 19

Find the value of x

replace the value of y in equation A until you get an integer value that satisfies the ratio 7:5

For y=19

$x=\frac{7}{5}(19)$

$x=26.6$

For y=18

$x=\frac{7}{5}(18)$

$x=25.2$

For y=17

$x=\frac{7}{5}(17)$

$x=23.8$

For y=16

$x=\frac{7}{5}(16)$

$x=22.4$

For y=15

$x=\frac{7}{5}(15)$

$x=21$

therefore

The greatest number of of bunches of bananas that Andrea can buy is 15 and the greatest number of boxes of raspberries that Andrea can buy is 21 to maintain the ratio 7:5

<u><em>Verify the inequality B</em></u>

$1.08[2.50(21)+3.00(15)]\leq 135$