Answer:the pages will come on the first is 210
Explanation:
Since we have given that two pages that face each other in a book
i.e. they must be consecutive to each other
so, let the first page number be x
and the second page number be x+1
According to question,

2x=421 -1
2x=420

So, the pages will come on the first is 210
Answer:
Out of every 5 rectangles 2 shall be purple.
3 scarves have 3 times 5 rectangles.
Thus they shall be 3 times 2 that are purple.
Step-by-step explanation:
Combination = doesn't matter what order
Permutation = order matters
There are <u>two</u> methods to work out combinations.
Method 1 List out possibilities
123 124 125 126 127 134 135 136 137 145 146 147 156 157 167
234 235 236 237 245 246 247 256 257 267
345 346 347 356 357 367
456 457 467
567
For a total of
35 combinations.
Method 2 Use a formula.
It's a rather complicated one, so only use it if you have a lot of possibilities.

(n is the number of choices, r is the amount you choose, and ! is a function that multiplies together all numbers down to 1)
Answer:
D
Step-by-step explanation
I'd say it's PQR and TSR cause they match up in terms of the order of vertexes, and then you've got the angles of P and T that are in the middle of PR and TR, which are equal, and the sides PQ and TS. The angles are in between the sides.
Complex roots occur when b^2 - 4ac is negative.
So we have (-6)^2 - 4.1.k < 0
-4k < - 36
k > 9