uses crt;

var i,n,dem:integer;

a:array[1..100]of real;

begin

clrscr;

write('Nhap so hoc sinh:'); readln(n);

for i:=1 to n do

begin

repeat

write('Nhap diem trung binh mon Tin Hoc cua ban thu ',i,'='); readln(a[i]);

until (0<a[i]) and (a[i]<=10);

end;

dem:=0;

for i:=1 to n do

if a[i]>=5 then inc(dem);

writeln('So ban co diem tren trung binh la: ',dem);

readln;

end.

uses crt;

var st:string;

i,d:integer;

begin

clrscr;

write('Nhap xau:'); readln(st);

d:=length(st);

for i:=1 to d do

if st[i]=' ' then st[i]:='_';

writeln('Xau sau khi thay doi la: ',st);

readln;

end.

uses crt;

var st:string;

i,d:integer;

begin

clrscr;

write('Nhap xau:'); readln(st);

d:=length(st);

for i:=1 to d do

if (st[i]='V') or (st[i]='v') then st[i]:='Z';

writeln('Xau sau khi thay doi la: ',st);

readln;

end.

Câu 1:

uses crt;
var ten:string;
kt:integer;
begin
clrscr;
write('Nhap ho va ten cua hoc sinh:'); readln(ten);
writeln('Ki tu thu 5 la: ',ten[5]);
kt:=0;
if ten[1] in ['A'..'Z'] then kt:=1;
if kt=0 then writeln('Ki tu dau tien chua viet hoa')
else writeln('Ki tu dau tien da viet hoa');
readln;
end.

Câu 2:

uses crt;
var d,r:real;
{-------------------------chuong-trinh-con----------------------------}
function dientich(x,y:real):real;
begin
dientich:=x*y;
end;
{-------------------------chuong-trinh-chinh---------------------------}
begin
clrscr;
repeat
write('Nhap chieu dai:'); readln(d);
write('Nhap chieu rong:'); readln(r);
until (d>0) and (r>0) and (d>=r);
writeln('Dien tich cua hinh chu nhat la: ',dientich(d,r):4:2);
readln;
end.

Câu 3:

uses crt;
var st:string;
dem,d,i:integer;
begin
clrscr;
write('Nhap xau:'); readln(st);
dem:=0;
d:=length(st);
for i:=1 to d do
if st[i] in ['0'..'9'] then inc(dem);
writeln('So ki tu chu so la: ',dem);
readln;
end.

uses crt;

var a:array[1..100]of integer;

i,n,t1,t2,dem1,dem2,max,min:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do

begin

write('A[',i,']='); readln(a[i]);

end;

t1:=0;

t2:=0;

dem1:=0;

dem2:=0;

for i:=1 to n do

begin

if a[i] mod 2=0 then

begin

inc(dem1);

t1:=t1+a[i];

end

else begin

inc(dem2);

t2:=t2+a[i];

end;

end;

writeln('Tong cac so chan la: ',t1);

writeln('So luong so chan la: ',dem1);

writeln('Tong cac so le la: ',t2);

writeln('So luong so le la: ',dem2);

max:=a[1];

min:=a[1];

for i:=1 to n do

begin

if max<a[i] then max:=a[i];

if min>a[i] then min:=a[i];

end;

writeln('Gia tri lon nhat la: ',max);

writeln('Gia tri nho nhat la: ',min);

readln;

end.

uses crt;
var s:string;
d,i:integer;
begin
clrscr;
write('Nhap xau S:'); readln(s);
d:=length(s);
writeln('Do dai cua xau la: ',d);
s:=upcase(s);
writeln('Xau S sau khi chuyen la: ',s);
for i:=1 to d do
if (s[i] in ['A'..'z']) or (s[i] in ['0'..'9']) then delete(s,i,1);
writeln('Xau S sau khi xoa cac ki tu la chu hoac so la: ',s);
for i:=1 to d do
if s[i]=' ' then delete(s,i,1);
writeln('Xau S sau khi xoa cac dau cach la: ',s);
readln;
end.

uses crt;

var a:array[1..50]of integer;

n,i,dem,tbc:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do

begin

write('A[',i,']='); readln(a[i]);

end;

writeln('Cac so chan la: ');

dem:=0;

tbc:=0;

for i:=1 to n do
if a[i] mod 2=0 then

begin

write(a[i]:4);

inc(dem);

tbc:=tbc+a[i];

end;

writeln;

writeln('So phan tu chan la: ',dem);

writeln('Trung binh cong cua cac so chan trong day la: ',tbc/dem:4:2);

readln;

end.

uses crt;

var st:string;

begin

clrscr;

write('Nhap xau:'); readln(st);

writeln('Ki tu dau tien la: ',st[1]);

writeln('Ki tu cuoi cung la: ',st[length(st)]);

readln;

end.