A) If 9 students sharpen 18 pencils in 2 minutes,Then if the time is halved, it will take twice as many men to sharpen 18 pencils.Hence it will take 18 students to sharpen 18 pencils in one minute B) y & 1/x. Then y = K/x where K is our constant of proportionality.Then K = yx. When x = -64 and y = -16 then K = -64 * -16 = 1024. Option DC) When x = 3 y = 8. So for an inverse variation K as calculated from B = 3 * 8 = 24.Then when K = 24 and y = 6; we have 24 = 6x. Hence x = 4. Option A
Note: a radioactive decay constant is always negative.
time = [natural log(ending amount / beginning amount)] / k
time = ln (20 / 24) / -.00011
time = ln (5/6) / -.00011
time = -.018232155683 / -.00011
time =
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<span>
165.7468698455
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</span>
</span>
time =
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165.75 years
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Answer:
2 hours
Step-by-step explanation:
Let x mph be the speed of motorboat in still water and y mph be the speed of current.
A raft and a motorboat simultaneously leave from the same point and move down the river, then speeds down the river are:
motorboat = x + y mph
raft = y mph
In two hours they will cover:
motorboat = 2(x+y) miles
raft = 2y miles
After 2 hours the motorboat turns around and starts moving towards the raft (against the current), so its speed is now x - y mph.
Let t be the time they move towards each other. In t hours, they cover
motorboat = t(x - y) miles
raft = ty miles
The distance from the starting point to the turning point is the same as the sum of the distances the raft covers and the motorboat covers after turning around, so

Answer:
8
Step-by-step explanation:
Recall the formula for the population mean of a data set:

We already know that μ is 6 and the sum is 48. Substitute:

Divide both sides by 48:

Reciprocal of both sides:

Thus, there are 8 scores in the population size.
And we're done!