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3 years ago

Can anyone help me with this

Mathematics

1 answer:

ANTONII [103]3 years ago

4 0

Answer:

Sure, what do you need

Step-by-step explanation:

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Half-life of Po-210 is 140 days. If the initial mass of the sample is 5

Anna35 [415]

Answer:

$0.625kg$

Step-by-step explanation:

we are given half-life of PO-210 and the initial mass

we want to figure out the remaining mass after 420 days

in order to solve so we can consider the half-life formula given by

$\displaystyle f(t) = a {0.5}^{t/T}$

where:

f(t) is the remaining quantity of a substance after time t has elapsed.
a is the initial quantity of this substance.
T is the half-life

since it halves every 140 days our T is 140 and t is 420. as the initial mass of the sample is 5 our a is 5

thus substitute:

$\displaystyle f(420)=5\cdot{0.5}^{420/140}$

reduce fraction:

$\displaystyle f(420)=5\cdot{0.5}^{3}$

By using calculator we acquire:

$\displaystyle f(420)=0.625$

hence, the remaining sample after 420 days is 0.625 kg

4 0

3 years ago

Ethan sold 2 3 gallon of lemonade. Kayla sold some lemonade too. Together, they sold 1 1 4 gallons. Who sold more lemonade, Etha

zhenek [66]

Step-by-step explanation:

Ethan sold 2/3 gallon of lemonade.

Kayla sold some lemonade too.

Together they sold 1 1/4 gallons.

Subtract 2/3 from 1 1/4 as follows :

$S=1\dfrac{1}{4}-\dfrac{2}{3}\\\\=\dfrac{5}{4}-\dfrac{2}{3}\\\\=\dfrac{7}{12}$

So, Kayla sold 7/12 gallons of lemonade.

As 2/3 is more than 7/12, it means Ethan sold more lemonade.

$\dfrac{2}{3}-\dfrac{7}{12}=\dfrac{1}{12}$

It means Eathn sold 1/12 more lemonade.

5 0

3 years ago

Sort each description of data into the appropriate category.

Alex787 [66]

Answer:

Step-by-step explanation:

Qualitative:

Eye colour

Grade level

favourite music group

Quantitive:

Capacity in litres

Height in inches

Number of siblings

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3 years ago

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Zeno is walking in a straight line. With each step, he covers half the remaining distance between him and the end of his path, w

shtirl [24]

8 foot path

1st step = 8/2 = 4ft
2nd step = 4/2 = 2ft
3rd step = 2/2 = 1ft
4th step = 1/2 = 1/2ft

So he covered 7 1/2 ft (or 7.5ft)

5 0

3 years ago

A boogie board that has a regular price of $69 is on sale at a 35% discount. What is the sale price with 7% tax? Please show how

rjkz [21]

Answer:

$47.99

Step-by-step explanation:

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