The cost of 1 battery is 0.43
Step-by-step explanation:
Let the cost of 1 battery be x
We are given that the torch costs 11 times as much as the battery
Cost of torch = 11x
Total cost of 1 battery and torch = 11x+x=12x
Tim pays $10
He receives change of $4.84
Total cost of 1 torch and battery = 10 - 4.84 =$5.16
So,


Hence the cost of 1 battery is 0.43
Answer:
image
Step-by-step explanation:
Answer:
9990 years
Step-by-step explanation:
The exponential function with given values filled in can be solved for the unknown using logarithms.
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Q(t) = 12 = 36e^(-0.00011t)
1/3 = e^(-0.00011t) . . . . . . divide by 36
ln(1/3) = -0.00011t . . . . . . take natural logs
t = ln(1/3)/(-0.00011) . . . . divide by the coefficient of t
t ≈ 9990 . . . years