Data:Range: 2 to 198Multiples of 10 are 10, 20, 30 ..... 190Since the numbers are in Arithmetic progression:First term = a = 10, Last term = tn= 190Difference = d = 20 - 10 = 10number of terms = nSum = SnFormula:tn = a + (n - 1)dSn = \(\frac{n(a + t_n)}{2}\)Calculation:190 = 10 + (n - 1) 10n = 19Sn = \(\frac{19(10 + 190)}{2} = 1900\)Average = \(\frac{1900}{19} = 100\) Tips and Tricks:\(Average = \frac{a + t_n}{2} = \frac{10 + 190}{2} = 100\)