a) Lower limit = 1st term = 1
Upper limit = 18th term = 18
b) We need to find the 18th term.....this is 3 + 7(18 - 1) =
3 + 7 * 17 =
122
The sum is given by :
[ 1st term + 18th term ] * number of terms / 2 =
[ 3 + 122 ] * 18 / 2 =
[ 125 ] * 9 =
1125 beads !!!
