diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index a317e22..05316d0 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -221,4 +221,5 @@ mod p3134_find_the_median_of_the_uniqueness_array;
 mod p3144_minimum_substring_partition_of_equal_character_frequency;
 mod p3142_check_if_grid_satisfies_conditions;
 mod p3153_sum_of_digit_differences_of_all_pairs;
-mod p3127_make_a_square_with_the_same_color;
\ No newline at end of file
+mod p3127_make_a_square_with_the_same_color;
+mod p1450_number_of_students_doing_homework_at_a_given_time;
\ No newline at end of file
diff --git a/src/problem/p1450_number_of_students_doing_homework_at_a_given_time.rs b/src/problem/p1450_number_of_students_doing_homework_at_a_given_time.rs
new file mode 100644
index 0000000..6797057
--- /dev/null
+++ b/src/problem/p1450_number_of_students_doing_homework_at_a_given_time.rs
@@ -0,0 +1,46 @@
+/**
+ * [1450] Number of Students Doing Homework at a Given Time
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn busy_student(start_time: Vec<i32>, end_time: Vec<i32>, query_time: i32) -> i32 {
+        let start_pos = start_time.iter().enumerate().filter_map(
+            |(pos, &value)| {
+                if value <= query_time {
+                    Some(pos)
+                } else {
+                    None
+                }
+            }
+        );
+
+        let pos = start_pos.filter_map(
+            |pos| {
+                if end_time[pos] >= query_time {
+                    Some(pos)
+                } else {
+                    None
+                }
+            }
+        );
+
+        pos.count() as i32
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1450() {
+        assert_eq!(1, Solution::busy_student(vec![1, 2, 3], vec![3, 2, 7], 4));
+        assert_eq!(1, Solution::busy_student(vec![4], vec![4], 4));
+    }
+}