Answer:
7 days
Step-by-step explanation:
At 25% per day, it will take approximately 3 days to double the population, so approximately 6 days for the population to quadruple. Checking that number, we find it is not quite enough for the experiment, so another day is required.
"Guess and check" as a method of solution works especially well if you have an automated checker to evaluate your guess. A graphing calculator or spreadsheet can work well for this.
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We guess 3 days as the doubling time using the "rule of 72" that says the product of percentage and doubling time is about 72. That is, 72/25 ≈ 3. (This is only a very rough approximation of doubling time, best for rates near 8%.)
396 out of 2800 shirts are defected.
396/2800 * 100 = 14.1% of the shirts were defected
we know that in direct variation as x increase y also increases.
in indirect variation x decreases y increase and vice versa.
in part a we have x at top (numerator ) and y at denominator it mean indirect variation (as x increases y decreases).
to find k we know that for indirect variation xy=k
if we rewrite the equation x=9/y we get xy=9
which mean k=9 .
in part b we have 4xy=20 if we simplify this equation we get
so here if we rewrite in terms of x.
we get x=5/y which represents indirect variation.
and we know xy=k
we have xy=5 .so k=5
Answer:
Explanation down below.
Step-by-step explanation:
10% of 91.25 = 9.125.
20% of 91.25 = 18.250.
30% of 91.25 = 27.375.
40% of 91.25 = 36.500.
36.500 × 2 = 73.
B, 70 dollars.
4: A school has 314 boys & 310 girls. If they are to be grouped into equal classes of 26 each , how many classes will there be?
314 boys + 310 girls = 624
If they are grouped into classes of 26 students each, how many class will there be?
130 students = 5 classes
Therefore
260 students = 10 classes
260 x 2 = 520 = 20 classes
26 x 24 = 624
Number of classes = 24
Question 5).
Jim worked 48 weeks last year. Each week he worked 38 hours. If he worked an additional 240 hours of overtime, how many hours did he work in all?
Solution:
48 weeks
24hrs × 7 = 168hrs
168 x 48 = 8,064
Additional 240hrs
= 168hrs = 7 days (a week)
240hrs - 168 = 72 (3days)
168 + 72
= 240hrs + 8, 064
= 8, 304 hrs
