5. The 5th figure will have 30 tiles. 6. The 6th figure will have 42 tiles. 7. The pattern is non-linear (quadratic). 8. The 20th figure can be made with 420 tiles.
_____ The Nth figure is made with n*(n+1) tiles. To answer question 8, you must solve .. n(n +1) = 420 .. n^2 +n -420 = 0 .. (n +21)(n -20) = 0 .. n = 20 or -21 . . . . the negative solution is extraneous
