Initially there is about 500 ml of air in our lungs. During normal breathing about 12% of the air in the lungs get replaced after one breath.
a) Write an exponential model to represent the amount of original air left in the
lungs.
b) Use the model to find out how much of the original air is present in the lungs after
25 breaths?
Note: the original air left in the long decrease with each breath.

im not sure

step-by-step explanation:

step-by-step explanation:

the answer is b

she will sew have sewn five dresses   and be 1/3 done with the sixth one in an hour.

step-by-step explanation:

3/4 of an hour=45 mins

lucy makes 1 dress per 11.25 minutes

45 mins+11.25 mins=56.25 mins

60 mins- 56.25 mins=3.75 mins

3.75 mins is 1/3 of of 11.25 mins

therefore she the other 1/3 would be part of the hour and she will have sewn 5 dresses and begun the sixth.

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