1)
s:=0;
for i:=1 to n do
if a[i] mod 10 = 7 then
s:=s+a[i];
2)
if a[i] mod 2 = 1 then
3)
if a[i] mod 4 = 0 then
1)
s:=0;
for i:=1 to n do
if a[i] mod 10 = 7 then
s:=s+a[i];
2)
s:=0;
for i:=1 to n do
if a[i] mod 2 = 1 then
s:=s+a[i];
3)
s:=0;
for i:=1 to n do
if a[i] mod 4 = 0 then
s:=s+a[i];