Câu 1:
uses crt;
var n,i,p:longint; s:string;
begin
clrscr;
repeat
write('Nhap so: '); readln(s);
until length(s)=3;
for i:=1 to length(s) do
if s[i]='0' then delete(s,i,1);
val(s,n);
p:=1;
while n<>0 do
begin
p:=p*(n mod 10);
n:=n div 10;
end;
writeln(p);
readln
end.
Câu 2:
uses crt;
var n,i,t,d:longint; s:string;
begin
clrscr;
repeat
write('Nhap so: '); readln(s);
until length(s)=4;
for i:=1 to length(s) do
if s[i] in ['0','2','4','6','8'] then inc(d)
else delete(s,i,1);
val(s,n);
while n<>0 do
begin
inc(t,n mod 10);
n:=n div 10;
end;
writeln('TBC: ',t/d:0:2);
readln
end.
Câu 3:
uses crt;
var n:longint;
begin
clrscr;
write('Nhap n: '); readln(n);
if n=sqr(trunc(sqrt(n))) then writeln(n,' la so chinh phuong')
else writeln(n,' khong phai so chinh phuong');
readln
end.