diff --git a/1661-average-time-of-process-per-machine/1661-average-time-of-process-per-machine.sql b/1661-average-time-of-process-per-machine/1661-average-time-of-process-per-machine.sql
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index 0000000..acb19de
--- /dev/null
+++ b/1661-average-time-of-process-per-machine/1661-average-time-of-process-per-machine.sql
@@ -0,0 +1,2 @@
+# Write your MySQL query statement below
+SELECT DISTINCT machine_id, ROUND((SELECT AVG(timestamp) FROM Activity a2 WHERE a2.machine_id = a1.machine_id AND activity_type = 'end')-(SELECT AVG(timestamp) FROM Activity a2 WHERE a2.machine_id = a1.machine_id AND activity_type = 'start'),3) AS processing_time FROM Activity a1;
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