$210
because if it rose 30%, it's now 130% of what is used to be
or (what it used to be) ×1.3
so do the reverse and divide the new cost by 1.3
so 273÷1.3 which is 210
10 razors......1 lasts for 1 week...so 10 would last for 10 weeks.
1 week = 7 days...so 10 weeks = 70 days.
6.30 / 70 = 0.09 per day (it would cost 9 cents per day)
2.66 is the speed
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Subtract 8 from both sides
So you end up with x = -23
The answer would be D. This is because in order to get W you would have to multiply 24 by the age (X) and add 8