Answer:
11
Step-by-step explanation:
Looking at Fibonacci numbers ;
We have:
Than X1 =1 ; X2 = 1; X3 = 2
Xn+1 = Xn + Xn-1
X3 = X2 + X1 = 1+1 =2; X4 = X3 + X2 = 2 +1 = 3; X5= X4+X3 = 3+2 = 5; X6 = X5 + X4 = 5 + 3 = 8; X7 = X6 +X5 = 8 +5 = 13; X8 = X7 + X6 = 13 + 8 = 21; X9 = X8 + X7 = 21+ 13 = 34 ; X10 = X9 + X8 = 34 +21 = 55 ; X11 = X10 + X9 = 55 +34 = 89
We see that ; X11 gives 89 so the value of n = 11
