If you plug in 7 for n, you get
(7+1)(7-2).
Simplify that.
(8)(5)
Simplify that and you get the 7th term of the particular sequence is,
40
Hope it helps :D
B)7:8 is the answer because:
16 total - 7 green = 8 and so
the ratio of GREEN to RED is
7:8
7 green 8 red
For a) it would be 1:2 as it is 16:8 and simplified would make it 1:2
15= 3*5
14= 2*7
LCM(15,14)= 2*3*5*7= 210
15 and 14 go into 210 evenly~