Answer:. 7
Step-by-step explanation:
Answer:
2.9 years
Step-by-step explanation:
Given that :
Half-life t1/2 = 9 years
Initial mass = I = 70 grams
A = final mass = 56 grams
t = time taken to reach final amount
Using the exponential half life relation :
A = I(0.5)^t/t1/2
56 = 70(0.5)^t/9
56/70 = 0.5^t/9
0.8 = 0.5^t/9
Log 0.8 = log 0.5^t/9
−0.096910 = −0.301029 * t/9
t/9 = 0.096910 / 0.301029
t/9 = 0.3219291
t = 0.3219291 * 9
t = 2.8973619
t = 2.9 years
Answer:
28
Step-by-step explanation:
Here is the complete question used in answering this question :
Three-fourths of the boats in the marina are white. 4/7 of the remaining boats are blue , and the rest are red . If there are 9red boats, how many boats are in the marina?
We first have to determine the fraction of the boats that are red
1 - (
+
)
1 - 
1 - 
1 - 1
= 9/28
so, 9/28 of the boats are red
let b represent the total number of boats
9/28 x b = 9
to find b, divide both sides of the equation by 28/9
b = 28
Answer:
1/12
Step-by-step explanation:
I just did this question and it was right :)
Thought I would help since I couldn't find the answer
The answer is falseeeeeeeee