Question

What are the values of these sums, where S={1,3,5,7}?
(a)∑(jϵS) j
(b)∑(jϵS) j^2
(c)∑(jϵS) (1/j)
(d)∑(jϵS) 1

Answer 1

Sum a.)

$1+3+5+7=16$

Sum b.)

$1^2+3^2+5^2+7^2=1+9+25+49=84$

Sum c.)

$1/1+1/3+1/5+1/7=$

$105/105+35/105+21/105+15/105=$

$176/105=1.6762$

Sum d.)

$1+1+1+1=4$