Answer:
4 hours 7 minutes
Step-by-step explanation:
Since Trevon takes 10 hours to clean the attic, he cleans 1/10, 10% or .1 of the attic per hour. Since Cody takes 7 hours to clean the attic, he cleans 1/7, 14.3% or .143 of the attic per hour.
Together, that means they clean .1 + .143 of the attic per hour. That's an hourly rate of:
.1 + .143 = .243
The portion of the attic they clean in x hours is .243x. We'd like to know how long it will take them to clean 100% or 1 of the attic. So:
.243x = 1 Divide each side by .243
x = 1/.243
x ≈ 4.115
Let's convert .115 to minutes by multiplying by 60
.115 * 60 = 6.9 round to 7 for 7 minutes
It will take them around 4 hours 7 minutes to clean the attic.
Answer:
k=9
Step-by-step explanation:
First find r=22/20=1.1
The sum of the first k terms formula is a1•(1-r^k)/(1-r)
a1=20 and the sum is 271.59
Now plug in these values in the formula and find k.
271.59=20(1-1.1^k)/(1-1.1)
When you simplify this equation, you will get k=ln(2.358)/ln(1.1)
k=9
Since it is odd, 4, 6 and 10 cannot be divisors.
5 cannot be a divisor since when you count by 5's you get numbers ending in 5 or 0
(5,10,15,20, etc)
9 cannot be a divisor since 9 x 6 = 54 and 9 sx 7 = 63
None of your answers will work with 57.
3 will work even though you did not list it. 5+7 = 12 and 1+2 = 3. If the sum of the digits = 3, 6 or 9, the number is divisible by 3.
45 is divisible by 3 (4+5=9)
78 is divisible by 3 (7+8=15 and 1+5 = 6)
Answer:
12 blueberries, 4 strawberries
Step-by-step explanation:
For every 3 blueberries, there is 1 strawberry. So 3 + 1 = 4
As there are a total of 16 berries in the bowl, 16/4 = 4 so there are 4 lots of "3 blueberries and 1 strawberry".
Therefore, there are 3 x 4 = 12 blueberries
1 x 4 = 4 strawberries
In other words — for any ingested substance to be naturally assimilated by the body, it must go through a series of chemical reactions, catalyzed by a specific portion of the electromagnetic light spectrum.
