20 possibilities based on this as a combination not a permutation, 6 nCr 3 = 20
(x+2) + 3(x+2)
x+2+3x+6
.. ( collect like terms )
= 4x+2+6
= 4x + 8 is your answer
First thing to do is set up your equation:
45/x = 20/100
Cross multiply
4500 = 20x
And divide by 20
Answer: 225 people were surveyed
the radius: r^2 = 81
r =9
c = 2*pi*r
= 2 * pi * 9
= 18 *pi
Answer: 18*pi or approximately 56.62
