Three times.
3 times because 7+7+7=21
1, 3, 7 and 21. Four numbers.
21 times with a remainder of 7
Three times
Three times.
7 times
21 feet.
21 goes into 147 seven times.
21 with remainder 7.
21, remainder 2
7, remainder 21
7 times with a remainder of 3