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4 years ago

I need help answering this ASAP please!

Mathematics

1 answer:

mariarad [96]4 years ago

8 0

Answer:

≈ 16 g

Step-by-step explanation:

Half life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half of its initial mass.

Therefore;

New mass = Original mass × (1/2)^n, where n is the number of half lives

Thus;

New mass = 125 × (1/2)³

= 125/8

= 15.625

≈ 16 g

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Round each number to the nearest... 100; 387,530

Lera25 [3.4K]

Answer:

<em>387 : 400, 530 : 500 would be your answer. </em>

4 0

4 years ago

total number of boys and girls in a class is 42. if the number of girls is 10 more than the boys find the number of boys?? answe

dsp73

Answer:

$\boxed{\sf Total \ number \ of \ boys = 16}$

Given:

Total number of boys and girls in class = 42

Total number of girls = 10 more than the boys

To Find:

Total number of boys

Step-by-step explanation:

Let total number of boys be 'x'

$\sf So, \\ \sf Total \: number \ of \ girls = x + 10 \\ \\ \therefore \\ \sf \implies Total \: number \: of \: boys \: and \: girls \\ \sf \: \: \: \: \: \: \: \: \: \: \: \: \: = Total \: number \: of \: boys + Total \\ \sf \: \: \: \: \: \: \: \: \: \: \: \: \: number \: of \: girls \\ \\ \sf \implies 42 = x + (x + 10) \\ \\ \sf 42 = x + (x + 10) \: is \: equivalent \: to \: x + (x + 10) = 42 : \\ \sf \implies x + (x + 10 )= 42 \\ \sf \implies x + x + 10 = 42 \\ \\ \sf x + x = 2x : \\ \sf \implies \boxed{ \sf 2x} + 10 = 42$

$\sf Substrate \: 10 \: from \: both \: sides : \\ \sf \implies 2x + (10 - \boxed{ \sf 10}) = 42 - \boxed{ \sf 10} \\ \\ \sf 10 - 10 = 0 : \\ \sf \implies 2x = 42 - 10 \\ \\ \sf 42 - 10 = 32 : \\ \sf \implies 2x = \boxed{ \sf 32} \\ \\ \sf Divide \: both \ sides \: by \: 2 : \\ \sf \implies \frac{2x}{ \boxed{ \sf 2}} = \frac{32}{ \boxed{ \sf 2}} \\ \\ \sf \frac{2x}{2} = \frac{ \cancel{2}}{ \cancel{2}} \times (x) = x : \\ \sf \implies x = \frac{32}{2} \\ \\ \sf \frac{32}{2} = \frac{16 \times \cancel{2}}{ \cancel{2}} = 16 : \\ \sf \implies x = 16$

So,

Total number of boys = x = 16

6 0

4 years ago

What division problem equals 184.32

Wewaii [24]

Answer:

There are many answers applicable to this question, one of them is 368.64/2 = 184.32

Step-by-step explanation:

All you have to do is multiply 184.32 times two. You can also try this with other numbers.

8 0

3 years ago

Complete the equation of the line through (-9,-9)(−9,−9)left parenthesis, minus, 9, comma, minus, 9, right parenthesis and (-6,0

saw5 [17]

Answer:

The equation of the line is;

y = 3x + 18

Step-by-step explanation:

We want to write the equation of the line through (-9,-9) and (-6,0)

we start by calculating the slope of the line

m = (y2-y1)/(x2-x1) = (0+ 9)/(-6+9) = 9/3 = 3

The general equation of the line is;

y = mx + c

y = 3x + c

To get c, we use any of the points

we substitute for example -6 for x and 0 for y

0 = 3(-6) + c

c = 0 + 18 = 18

So the equation of the line is;

y = 3x + 18

4 0

3 years ago

A and B can do a work in 3 days but A working alone takes 4 days. In what time will B do it if he works alone?

zalisa [80]

Answer:

Let B have x days work:

A + B = 3 days

1/4 + 1/x = 1/3

1/3 - 1/4 = 1/x

1/12 = 1/x

x = 1 / (1/12)

x = 12

B takes 12 days

I do not know if this is right

O O

(____)

6 0

3 years ago