Evaluate
0.30+0.31+0.32+0.33+0.34...+0.47+0.48+0.49+0.50
Express your answer as a decimal.
This should be easy. Multiply the expression by 100 then group then divide. Steps:
30+31+32+...+49+50
80 x 10
800
800/100=8
This is an arithmetic series, first term = 0.30, last term = 0.50, with the number of terms = 21.
A formula for the sum of an arithmetic series is: Sum = [ number · (first + last) ] / 2
Sum = [ 21 · (0.30 + 0.50) ] / 2
Sum = 8.40
This can be checked by summing all the individual terms.