Answer:
4
Step-by-step explanation:
x butterflies and y dragonflies
4 < x + y 《 8
x = 2y
4 < 2y + y < 8
4 < 3y < 8
Only multiple of 2 between 4 and 8 is 6
So 3y = 6
y = 2
x = 2y = 4
Answer: A (10)
Step-by-step explanation:
Running time for 1 day = 15
Running time for 1 week = 15*7= 105
So, yes she has completed her goal
I would say 270 because : 30 times 9 is 270.
Answer:
- half-life: 95.3 days
- 60% life: 70.2 days
Step-by-step explanation:
a) The proportion remaining (p) after d days can be described by ...
p = (1 -0.73)^(d/180) = 0.27^(d/180)
Then p=1/2 when ...
0.50 = 0.27^(d/180)
log(0.50) = (d/180)log(0.27)
180(log(0.50)/log(0.27) = d ≈ 95.3
The half-life is about 95.3 days.
__
b) For the proportion remaining to be 60/100, we can use the same solution process. In the end, 0.50 will be replaced by 0.60, and we have ...
d = 180(log(0.60)/log(0.27) ≈ 70.2 . . . days
60 mg will remain of a 100 mg sample after 70.2 days.
