Question

find the 45th term of the series: 9,91,19,911,191,119,9111,1911,1191,1119,...
pls help and don't spam :(​

Answer 1

Answer:

111111119

STEP BY STEP

9 There is no 1 after 9 so we can write one time (9).Count = 1

91 There is a one after 9 we can write in 2 ways

(91,19).Count = 2+1= 3

911 There's two ones after 9 so 8n 3 ways

(911,191,119).Count =3+3=6

9111 we get 4 terms Count =6+4=10

91111 we get 5 terms 10+5 = 15

911111 we get 21

91111111 we get 29

911111111 we get 34

9111111111 we get 45

Our 45 term is 1111111119