Question

without adding,find the sum
a) 1+3+5+7+9
b) 1+3+5+7+9+11+13+15+17+19​

Answer 1

Answer:

a) 1+3+5+7+9=25

b) 1+3+5+7+9+11+13+15+17+19=100

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Answer 2

Step-by-step explanation:

S=n/2(a+l)

(s=sum,. n= no. of tur terms, a= first term, l=last term)

a). 5/2(1+9)

=5/2×10

=25

b)10/2(1+19)

5×20

100