Question

Use a for loop in Matlab to create an array containing the first 1,000 Fibonacci numbers. Then determine how many of those numbers are divisible by 3.

Answer 1

In fibonacci series t(1)=1,t(2)=1 and t(n)=t(n-1)+t(n-2)

Matlab code for the above program explained in comments:

%Declare an empty array
x=[];
%Insert 1 two times in it
t1=1;
t2=2;
x=[x,t1];
x=[x,t2];
%Now for remaining 998 fibonacci numbers iterate thorugh the loop
for i = 1:1:998
tmp=t2;
t2=t1+t2;
t1=tmp;
x=[x,t2];
end
%Initialize count as 0
count=0;
%Iterate through array x and if the number is divisibe by 3 then increment count
for i=1:1000
if mod(x(i),3)==0
count=count+1;
end
end
%Print total fibonacci numbers divisible by 3
fprintf("Total fibonacci numbers divisible by 3= %d",count);

Output:

octave:18> source("my_script.m") Total fibonacci numbers divisible by 3= 846

Total fibonaaci numbers divisible by 3 are 846