Help 14, ​15,16

14

We have the following  [geometric ] pattern

22,  17.6 , 14.08

The common ratio  is     17.6 / 22   = 4/5

So.....we want to find this

22(4/5)^n  = 10

(4/5)^n  = 10/22

(4/5)^n  = 5/11      take the log of both sides

log (4/5)^n  = log (5/11)

n * log (4/5)  = log (5/11)

n =  log (5/11)  / log (4/5)  ≈  3.5

Thus...we need to round this up to 4

So....the 4th square will have a side length of  < 10  inches

15

50th term of   -2, 4, 8 , 14

This is an arithmetic series with a  common difference  of 6

So....the 50 th term is

-4  + 6 (49)   =

290

16

20th  term of 

-2   4  -8    16

This is a geometric series where the nth term can be represented as

(-2)^n

So....the 20 th   term is

(-2)^20  =

1048576