In the adjoining figure , O is the centre of the circle and PQ is the diameter .Show that angle PQR is a right angle .

Mathematics

1 answer:

Makovka662 [10]3 years ago

7 0

Answer:

Step-by-step explanation:

PRQ is the right angle. It is the angle opposite a diameter which is 90 degrees.

PQR is an acute angle. I can make no other statement about it without one more piece of information.

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If you measure a tds of 1.4%, and you used a brew ratio of 15, what is the percent extraction?

sweet-ann [11.9K]

Answer: the extraction is 18.2%.

Explanation:

Let's see few definitions:
TDS = Total Dissolved Solids = solids dissolved in the brew
PE = Percent Extraction = percent of solids extracted from the dry coffee grounds

The percent extraction can be calculated by the formula:
PE = TDS × Rm

where
Rm = ratio between the mass of the brew and the mass of dry grounds

Now, you need to consider the following facts:
1) every 1g of coffee absorbs 2g of water
2) the given brew ratio is 1:15, which means that for every 1g of grounds we use 15g of water

Let's call
x = grams of coffee grounds we want to use
Therefore the mass of the brew will be:
m(brew) = water we use - water absorbed by the coffee
= 15·x - 2·x
= 13·x

Therefore,
Rm = m(brew) / x
= 13·x / x
= 13

Hence, the percent of extraction will be:
PE = TDS × Rm
= 1.4 × 13
= 18.2

4 0

3 years ago

A. 3/19 B. 4/19 C. 1/5 D. 5/19

DanielleElmas [232]

$P(B|A)=\dfrac{P(A \cap B)}{P(A)}\\\\ |\Omega|=20\cdot19=380\\ |A|=5\cdot19=95\\ |A\cap B|=5\cdot4=20\\\\ P(A)=\dfrac{95}{380}=\dfrac{1}{4}\\ P(A \cap B)=\dfrac{20}{380}=\dfrac{1}{19}\\\\ P(B|A)=\dfrac{\dfrac{1}{19}}{\dfrac{1}{4}}=\dfrac{1}{19}\cdot4=\dfrac{4}{19}\Rightarrow B$