What occurs when ice melts? A. a chemical change B. a physical change C. a nuclear change D. An atomic compound is newly
2 answers:
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Answer: There are 20 ways and 1680 ways respectively.
Step-by-step explanation:
Since we have given that
Total number of blocks = 6
Number of red blocks = 3
Number of green blocks = 3
So, Number of patterns she can make by placing them all in a line is given by
If there are 3 white blocks
so, total number of white blocks becomes 9
So, Number of total pattern she can make by placing all nine blocks in a line is given by
Hence, there are 20 ways and 1680 ways respectively.
Answer:
D
Step-by-step explanation:
Parallel lines have the same gradient.
A line with a slope of zero is a horizontal line. Although two lines that have a slope of zero will result in two parallel lines, not all parallel lines are horizontal lines. Since the question is asking for which statement <u>must</u> be true, option A is incorrect.
If the slopes of two lines are negative reciprocals, they are perpendicular to each other. This is because the product of the gradients of 2 perpendicular lines is -1. Let the gradient of the first line be A and the other be B.
AB= -1
Thus, option B is incorrect too.
Undefined slopes gives vertical lines. Like option A, if two lines have an undefined slope, they will be parallel to each other. However since parallel lines are nit necessarily vertical lines, option C is also incorrect.