Answer:
5.1 days
Step-by-step explanation:
Given in the question,
initial amount of substance = 34 grams
k-value = 0.137
To find the half life of this substance we will use following formula

here N(0) is initial amount of substance
t is time in days
Plug values in the formula

1/2 = e^{-0.137t}
Take logarithm on both sides
ln(1/2) = ln( e^{-0.137t})
ln(1/2) = -0.137t
t = ln(1/2) / -0.137
t = 5.059
t ≈ 5.1 days (nearest to tenths)
Answer:
Y=x+8
Step-by-step explanation:
To find the gradient of the line u have to subtract the y intercepts and the x intercepts
10-7/2--1=3/3=1
Y-7/x--1=1
Y-7=x+1
Y=x+1+7
Y=x+8
X = bessie and y = betty
x + y = 1464
y = 2x - 375
x + 2x - 375 = 1464
3x - 375 = 1464
3x = 1464 + 375
3x = 1839
x = 1839/3
x = 613 <== Bessie gave 613 gallons
y = 2x - 375
y = 2(613) - 375
y = 1226 - 375
y = 851 <== Betty gave 851 gallons
Approximately 19.2% of the world would not have clean drinking water.