PHP stuck with the loop excercise - php

Question

I am stuck with this php loop. Then n = 3, k = 5, s = 21.
Can anyone help me please ?
Rows 3. In the first row 5 chairs:
1 row: ⑁⑁⑁⑁⑁ (5 chairs)
2 row: ⑁⑁⑁⑁⑁⑁⑁ (7 chairs)
3 row: ⑁⑁⑁⑁⑁⑁⑁⑁⑁ (9 chairs)
Chairs in total: 21
<?php
for ($i=0; $i<=6; $i++) {
for ($j=0; $j<$i; $j++) {
if($i == 1) {
echo '';
}else{
echo '&#9281';
}
} echo ' ';
}
?>

Answer 1

If I understand correctly what you want,
$n is number of row you needed,
$k number of chair at row 1.
Each row chair is added by two.
<?php
$n = 3;
$k = 5;
for($i = 0; $i < $n; $i++) {
if($i >= 1) {
echo PHP_EOL;
}
echo str_repeat('-', $k + ($i * 2));
}

Answer 2

Example: When n = 3 and k = 8, it must be obtained that order s = 30 chairs.
Create a PHP solution that specifies the N-row queue in the variables, K-how many chairs should be in the first row.
For example: N = 3; K = 5;
After loading the page (after performing the program actions with the variables available) the following should be displayed:
Rows 3. First row 5 chairs:
Queue 1: ⑁⑁⑁⑁⑁ (5 chairs)
Queue 2: ⑁⑁⑁⑁⑁⑁⑁ (7 chairs)
Queue 3: ⑁⑁⑁⑁⑁⑁⑁⑁⑁ (9 chairs)
Total required chairs: 21

Answer 3

I think you want to use 'if' syntax. Is it right?
If it's not correct, You should describe your work more detail
<?php
// ...
for($i = 0; $i< sizeof($rows); $i++ ){
if ($i % 2 == 0) {
print "It's even";
}
}
// ... If a row is an Array, use this one.
for($i = 0; $i< sizeof($rows); $i++ ){
for($j = 0; $j< sizeof($rows[$i]); $j++ ){
if ($j % 2 == 0) {
print "It's even index of a row";
//do Something.
}
}
}
?>