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3 years ago

7

Notebooks cost $1.20 each. This weekend they will be $.80 What percentage is the sale?

1 answer:

geniusboy [140]3 years ago

6 0

The sale is 33% off notebooks. This can be found by first subtracting .8 from 1.2

1.2-.8=.4 Now divide .4 by 1.2 to get your answer.

$\frac{.4}{1.2}$ =.33

.33=33%

You can also solve this mentally because if you know your basic multiplication tables, 3*4=12 and so $\frac{2}{3}$ of 12 would equal 8.

Does you understand it now?

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5 2 1 2 <br><br>3 3 4 5 <br><br>5 4 3 3 <br><br>4 5 1 2 <br><br>calculate the mean of the data

MAXImum [283]

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3 years ago

Yuri has 2/7 of a bag of carrots.if she eats half of the carrots,what fraction of the bag of carrots will she have left

Alisiya [41]

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3 years ago

A flat rate shipping box is in the shape of a rectangular prism. You estimate that the volume of the box is 350 cubic inches. Yo

kirill115 [55]

14.4%

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3 years ago

The area of a triangle is 36 4 5 units squared and the height of the triangle is 9 1 5 units. What is the length of the triangle

Zinaida [17]

Answer:

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Step-by-step explanation:

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3 years ago

A lighthouse is located on a small island 5 km away from the nearest point P on a straight shoreline and its light makes seven r

Vaselesa [24]

Answer:

Light is moving at the speed = 77.78 km/min

Step-by-step explanation:

Given:

Distance between island and point P = 5 km

Moving along the the shoreline when it is 1 km from P.

So, x = 1

From the above statement light makes seven revolutions per minute.

Therefore,

$\frac{d\theta}{dt}=\frac{7\times 2\pi\ rad}{1\ min} = 14\pi\ rad/min$

Solution:

From the given figure.

$tan\theta=\frac{x}{5}$

Substitute x = 1

$tan\theta=\frac{1}{5}$ -------------------(1)

Now, first we differentiate both side with respect to t.

$\frac{d(tan\theta)}{dt} = \frac{d}{dt}.(\frac{x}{3})$

Using chain rule.

$\frac{d(tan\theta)}{dt}.\frac{d\theta}{dt} = (\frac{1}{5})\frac{dx}{dt}$

$sec^{2} \theta.\frac{d\theta}{dt} = \frac{1}{5}.\frac{dx}{dt}$

$(1+tan^{2} \theta).\frac{d\theta}{dt} = \frac{1}{5}.\frac{dx}{dt}$

Substitute $tan\theta=\frac{1}{5}$ from equation 1.

$(1+(\frac{1}{3})^{2} ).\frac{d\theta}{dt} = \frac{1}{5}.\frac{dx}{dt}$

$(1+\frac{1}{9}).\frac{d\theta}{dt} = \frac{1}{5}.\frac{dx}{dt}$

Substitute $\frac{d\theta}{dt}=14\pi$

$\frac{10}{9}.14\pi = \frac{1}{5}.\frac{dx}{dt}$

Applying cross multiplication rule.

$\frac{dx}{dt}= \frac{700\pi }{9}$

$\frac{dx}{dt}= 77.78\pi$

Therefore, light is moving along the shore at the speed of 77.78 km/min

6 0

4 years ago