Question 1058987
It is 5000+4000+3200, and each day 0.80 of the prior day seeps in.
The eventual amount is 5000/(1-0.80)=5000/0.2=25,000 liters ANSWER D
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A*r^4, which is r^(5-1) is 5000*(.8^4)=2048 liters.
Can also continue from above, where day 4 is 2560 and day 5 is 2048. ANSWER A
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Through day 5, it is 12200+2560+2048=16,808 l ANSWER B
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20000=A (1-r^n)/(1-r)
4*(1-r)=(1-r^n)
0.8=1-r^n
-0.2=-r^n
r^n=0.2
ln both sides and ln r=-0.223
n ln r=ln (0.2)
n=ln(0.2)/ln 0.8)=-1.609/-.223
n=7.21 days  ANSWER C
Day 6 will have 1638.4 l.
Day 7 will have 1310.7 l
The sum through day 7 is 12200+2560+2048+1638.4+1130.7=19576.7 l, which checks.