13, because 78 postcards divided by 6 cards per board = 13 poster boards
Answer:
1.30 p.M.
Step-by-step explanation:
The factory whistle blowed at 1:00 p.M, and it blows every 30 minutes, so it will blow again at 1:30 p.M.
The clock tower chimed at 1.00 p.M., and it chimes every 15 minutes, so it will chime again at 1:15 p.M, and after that, it will chime again at 1:30 p.M.
So, you will hear them both at the same time at 1:30 p.M.
We can also solve this problem using LCM:
the least commom multiple between 15 and 30 is 30, so we just need to sum 30 to the inicial time (1:00 p.M.), so the time they will "find each other" again is 1.30 p.M.
You have not given us any of the steps that Ricardo took to simplify the
expression, and you also haven't given us the list of choices that includes
the description of his mistake, so you're batting O for two so far.
Other than those minor details, the question is intriguing, and it certainly
draws me in.
If Ricardo made a mistake in simplifying that expression, I'm going to say that
it was most likely in the process of removing the parentheses in the middle.
Now you understand that this is all guess-work, because of all the stuff that you
left out when you copied the question, but I think he probably forgot that the 3x
operates on everything inside the parentheses.
He probably wrote that 3x (x-3) is
either 3x² - 3
or x - 9x .
In reality, when properly simplified,
3x (x - 3) = 3x² - 9x .
Answer:
1. 13.65, 136.5, 1365
2. 57.14, 5.714, .5714
Step-by-step explanation:
