Answer:
0.75 mg
Step-by-step explanation:
From the question given above the following data were obtained:
Original amount (N₀) = 1.5 mg
Half-life (t₁/₂) = 6 years
Time (t) = 6 years
Amount remaining (N) =.?
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t₁/₂) = 6 years
Time (t) = 6 years
Number of half-lives (n) =?
n = t / t₁/₂
n = 6/6
n = 1
Finally, we shall determine the amount of the sample remaining after 6 years (i.e 1 half-life) as follow:
Original amount (N₀) = 1.5 mg
Half-life (t₁/₂) = 6 years
Number of half-lives (n) = 1
Amount remaining (N) =.?
N = 1/2ⁿ × N₀
N = 1/2¹ × 1.5
N = 1/2 × 1.5
N = 0.5 × 1.5
N = 0.75 mg
Thus, 0.75 mg of the sample is remaining.
Eight-year-olds can count to the highest number
Answer:
1 and 2 answers are correct
Step-by-step explanation:
2x-y= -8
x-y = -4
ADD BOTH (y is cancelled)
3x= -12
x= -4
-8+y=-8
y=0
-4-y = -4
Multiply all by -1
4+y=4
y=0
<h3>Given</h3>
A(-3, 1), B(4, 5)
<h3>Find</h3>
coordinates of P on AB such that AP/PB = 5/2
<h3>Solution</h3>
AP/PB = 5/2 . . . . . desired result
2AP = 5PB . . . . . . multiply by 2PB
2(P-A) = 5(B-P) . . . meaning of the above
2P -2A = 5B -5P . . eliminate parentheses
7P = 2A +5B . . . . . collect P terms
P = (2A +5B)/7 . . . .divide by the coefficient of P
P = (2(-3, 1) +5(4, 5))/7 . . . . substitute the given points
P = (-6+20, 2+25)/7 . . . . . . simplify
P = (2, 3 6/7)
