Answer:
19.44 hours, about 19 hours 26 minutes
Step-by-step explanation:
The exponential equation that describes your caffeine level can be written as ...
c(t) = 120·(1 -0.12)^t . . . . where t is in hours and c(t) is in mg
We want to find t for c(t) = 10, so ...
10 = 120(0.88^t)
10/120 = 0.88^t . . . . . . . divide by 120
log(1/12) = t·log(0.88) . . . take logarithms
t = log(1/12)/log(0.88) ≈ 19.4386
It will take about 19.44 hours, or 19 hours 26 minutes, for the caffeine level in your system to decrease to 10 mg.
Yes, of course there'd be white
Interest paid by Linda is equal to $4.272 approximately equal to $4.27.
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Solution:
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Given that
Rate of interest on first $200 = 1.8%
Rate of interest on any amount over $200 = 1.2%
Unpaid balance amount of Linda’s credit card bill = $256
Need to calculate interest paid by her on $256.
Unpaid balance = $256
=$200 + 56
Amount over $200 = 56
Interest paid on first $200 = 1.8% of 200
= 0.018 x 200 = $3.6
Interest paid on amount over $200 that is $56 = 1.2% of 56
= 0.012 x 56 = $0.672
So total interest paid on $256 = 3.6 + 0.672 = $4.272.
Hence interest paid by Linda is equal to $4.272 approximately equal to $4.27.
