Answer:
C. √2 - 1
Step-by-step explanation:
If we draw a square from the center of the large circle to the center of one of the small circles, we can see that the sides of the square are equal to the radius of the small circle (see attached diagram)
Let r = the radius of the small circle
Using Pythagoras' Theorem 
(where a and b are the legs, and c is the hypotenuse, of a right triangle)
to find the diagonal of the square:



So the diagonal of the square = 
We are told that the radius of the large circle is 1:
⇒ Diagonal of square + r = 1





Using the quadratic formula to calculate r:




As distance is positive,
only
Which one do you need help on
520 pages. 390 divided by 3 is 130. Take that times 4 and you get 520. To check it, I took 520 divided by four (or you can multiply by 1/4) and got 130. Hope it helps!
There are 52 cards in the deck.
Picking a spade would be 13/52 which reduces to 1/4
After the first card is picked there are 51 cards left, picking a club would be 13/51
Picking both would be 1/4 x 13/51 = 13/204
The answer is C.
Answer: b
Step-by-step explanation: 19 x 3 = 57 & 12 x 3= 36 so subtract 57 and 36 that’s going to give you 21 & 21 plus 6 is 27