<span>It doesn't matter that she guessed correctly on the first two questions, guessing the third question correctly is independent of guessing any other question correctly. Therefore, the probability is one out of four, 1/4.</span>
23,718<span>
The 2
is in the ten thousands place. There is a 3 in the thousands place. Since 3 is less than 5, 2 stays the same and everything after it turns into 0s.
20,000
Answer: 20,000</span>
Answer:
<em>9*364 - 9*125 - 9*39 = 1,800</em>
Step-by-step explanation:
<em>Mental Calculation</em>
If we detect known patterns in the calculations, we could easily give their results without the use of calculators.
We are given the expression to evaluate:
9*364 - 9*125 - 9*39
The first thing to note is the 9 is a common factor of all terms, thus we take it out:
9*(364 - 125 - 39)
The negative numbers can be easily added
125
+ 39
------------
164
Now our expression is much easier:
9*(364 - 164)
The subtraction of 364-164 is 200, thus the result of the operations is:
9*200. We only need to recall 9*2=18 and add two zeros to get 1,800, thus:
9*364 - 9*125 - 9*39 = 1,800
Let p be the pre-tax cost. Then 1.08p = $50. Solving for p, the pre-tax cost, we get:
p = ($50) / (1.08) = $46.30.
