3 years ago

Pls help with question.

Mathematics

1 answer:

BigorU [14]3 years ago

4 0

Answer:

4a) 4 1/6

4b) 2

5a) 36.424

5b) 5.4

Step-by-step explanation:

When multiplying or dividing by mixed numbers, convert them into improper and just do it from left to right for each numerator and denominator

You might be interested in

Whats the mean of 72+72+72+79+82+82+88?

creativ13 [48]

Answer:

78.1428571429

Step-by-step explanation:

6 0

2 years ago

What is the x-coordinate of the solution to the system?<br> { 2x-3y= -27<br> -3x+2y= 23

UkoKoshka [18]

Answer:

x = 41 and y = 76

Step-by-step explanation:

4 0

2 years ago

Read 2 more answers

What is 199 times 347

marusya05 [52]

Answer:69,053

Step-by-step explanation: my bad i added it the frist time lol

7 0

2 years ago

Read 2 more answers

The area of a rectangle is 336 square inches. If the width of a rectangle is 6 inches. What is the length of the rectangle?

Hoochie [10]

The length of the rectangle is 56

6 0

3 years ago

Read 2 more answers

The core melt- down and explosions at the nuclear reactor in Chernobyl in 1986 released large amounts of strontium-90, which dec

elena-14-01-66 [18.8K]

If $S(t)$ is the amount of strontium-90 present in the area in year $t$ , and it decays at a rate of 2.5% per year, then

$S(t+1)=(1-0.025)S(t)=0.975S(t)$

Let $S(0)=s$ be the starting amount immediately after the nuclear reactor explodes. Then

$S(t+1)=0.975S(t)=0.975^2S(t-1)=0.975^3S(t-2)=\cdots=0.975^{t+1}S(0)$

or simply

$S(t)=0.975^ts$

So that after 50 years, the amount of strontium-90 that remains is approximately

$S(50)=0.975^{50}s\approx0.282s$

or about 28% of the original amount.

We can confirm this another way; recall the exponential decay formula,

$S(t)=se^{kt}$

where $t$ is measured in years. We're told that 2.5% of the starting amount $s$ decays after 1 year, so that

$0.975s=se^k\implies k=\ln0.975$

Then after 50 years, we have

$S(50)=se^{50k}\approx0.282s$

5 0

3 years ago