Honestly, I find Mrs. Garcia's method easier to perform mentally. It hinges on how familiar you are with your multiples of 5. (5*15 = 75 is a multiplication I often use)
Melissa's approach involves calculating 5*20 = 100 and 5*9 = 45, then combines the 3-digit result 100 with the 2-digit result 45, yielding 145. Adding 45 to 00 is simple and doesn’t require carrying digits, thus the arithmetic is fairly straightforward.
Mrs. Garcia's technique involves computing 5*14 = 70 and 5*15 = 75, then summing these two-digit results. Many people may not readily recall that 5*15=75, which complicates forming that product. The addition of 70 and 75 requires a carrying operation, making the math somewhat more complex. The resulting total is 145.
(The rationale behind my preference for Mrs. Garcia's method is that I can achieve the final sum by simply doubling 7 tens, followed by adding 5. The only 3-digit number to remember mentally is the ultimate total.)
_____Subtraction introduces a slight complication, yet reshaping it as $5(30 -1) = $150 - 5 = $145 is possible.
Or, you may reframe it as $5(28 +1) = $140 +5 = $145.
Dividing an even number by 2 to find the product of 5 is straightforward when you append a zero.
5*14 = 10*7 = 70
5*28 = 10*14 = 140.
Answer:
The correct answer is;
A. 0.17
Step-by-step explanation:
Here are the provided details;
The average time taken for a cashier to handle an order, μ = 276 seconds
The deviation from the average, σ = 38 seconds
The z-score for an order processing time of x = 240 seconds can be calculated as follows;

Thus;

The resulting probability
P(z = -0.9474) = 0.17361
Hence, the estimated proportion of orders processed in under 240 seconds is roughly 0.17361 or 0.17 when rounded to two decimal places.
Correct question:
An urn holds 3 red and 7 black balls. Players A and B take turns withdrawing balls until a red one is chosen. Calculate the probability that A picks the red ball. (A goes first, followed by B, with no replacement of drawn balls).
Answer:
The likelihood that A picks the red ball is 58.33 %
Step-by-step explanation:
A will select the red ball if it is drawn 1st, 3rd, 5th, or 7th.
1st draw: 9C2
3rd draw: 7C2
5th draw: 5C2
7th draw: 3C2
Calculating for all possible scenarios gives us:
9C2 = (9!) / (7!2!) = 36
7C2 = (7!) / (5!2!) = 21
5C2 = (5!) / (3!2!) = 10
3C2 = (3!) / (2!) = 3
Adding these possibilities results in 36 + 21 + 10 + 3 = 70.
The total outcomes for selecting a red ball = 10C3
10C3 = (10!) / (7!3!)
= 120.
The probability that A selects the red ball is determined by dividing the sum of possible events by the overall outcomes.
P( A selects the red ball) = 70 / 120
= 0.5833
= 58.33 %
The unidentified quantity is the framed prints (517)
The least common denominator needed to combine the variable terms is 15. The least common denominator for the constant terms is 21.