As an improper fraction, it is
.
You'll have to set this up as two separate problems. First, we want to take 15% off the original $20 bill. To do this, you're going to multiply 20 by .15, which gives you $3. So, 15% off $20 is $17.
Now, we want to find 7% of the new bill, so we're going to multiply 17 by .07 to get $1.19, and add it to the $17, making the final bill $18.19. You could also multiply $17 by 1.07 to get your final total without the extra step in the middle, but only do that once you're comfortable with the math.
Pls give brainiest
<h3>
Answer: 375</h3>
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Work Shown:
a = 300 = first term
r = 60/300 = 0.2 = common ratio
We multiply each term by 0.2, aka 1/5, to get the next term.
Since -1 < r < 1 is true, we can use the infinite geometric sum formula below
S = a/(1-r)
S = 300/(1-0.2)
S = 300/0.8
S = 375
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As a sort of "check", we can add up partial sums like so
- 300+60 = 360
- 300+60+12 = 360+12 = 372
- 300+60+12+2.4 = 372+2.4 = 374.4
- 300+60+12+2.4+0.48 = 374.4+0.48 = 374.88
and so on. The idea is that each time we add on a new term, we should be getting closer and closer to 375. I put "check" in quotation marks because it's probably not the rigorous of checks possible. But it may give a good idea of what's going on.
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Side note: If the common ratio r was either r < -1 or r > 1, then the terms we add on would get larger and larger. This would mean we don't approach a single finite value with the infinite sum.
