SOLUTION: Find the sum of the first 60 terms of the arithmetic sequence 14, 19, 24, 29.....

a2 - a1 = 19 - 14 = 5
a3 - a2 = 24 - 19 = 5
a4 - a3 = 29 - 24 = 5

Therefore the common difference d = 5

Sn = [2a1 + (n-1)d]

S60 = [2(14) + (60-1)5]

S60 = 30[28 + (59)5]

S60 = 30[28 + 295]

S60 = 30[323]

S60 = 9690

Edwin