9 and 3/8 is 75/8 as a mixed #.
Answer:
<h2><<The factors of 12 are 1, 2, 3, 4, 6, and 12, because each of those divides 12 without leaving a remainder (or, alternatively, each of those is a counting number that can be multiplied by another counting number to make 12).</h2>
Answer:
B
Step-by-step explanation:
Answer is 35
Let
R = Ralph's age
S = Sara's age
First statement is translated as:
S = 3R
Second statement is translated as:
S + 4 = 2(R + 4)
Use the first equation to be substituted into the second one in terms of R which is the one we are actually going to solve for Ralph's age.
Since S = 3R, then
3R + 4 = 2(R + 4)
3R + 4 = 2R + 8
3R - 2R = 8 - 4
R = 4 years old
Answer:
as written: 2500.2
as intended: 3000
Step-by-step explanation:
20% = 0.2, so adding 0.2 to 2500 gives 2500.2
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We suspect you want to add 20% of 2500 to 2500. That is ...
2500 + 20%×2500
= 2500 + 0.20×2500
= 2500 + 500
= 3000
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<em>Comment on percentages</em>
A percentage is a pure number. It is a ratio of like quantities, so has no units.* A <em>useful</em> percentage always has a base. That is, it is a percentage <em>of something</em>. Sometimes that base may be unclear or unstated, in which case the percentage might very well be considered to be meaningless.
In any event, a percentage is simply a (unitless) fraction. The "%" symbol means the same thing as "/100", so 20% means 20/100 = 2/10 = 1/5.
The very clear math expression 2500 +20% means simply 2500 + 1/5, which is the mixed number 2500 1/5 or the decimal value 2500.2. Usually, when we want to add a percentage to some value, we want the percentage to be <em>of the original value</em>. When that is written as a math expression, it must show this:
2500 + 20% of 2500
2500 + 20%×2500
2500(1 +20%)
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* The concentration or potency of some medicines or other mixtures may be expressed as a percentage that is the ratio of one unit to a different unit, typically weight per volume. That is, a "0.1%" preparation may be 0.1 grams per 100 mL, for example. You have to read the label to determine whether this is the case. Mathematically, this is not a percentage, but is a non-standard use of the "%" symbol to indicate a ratio to 100 of something.
