Question

without adding ,find the sum 1+3+5+7+9+11+13+15+17+19+21++23+25+27++29

Answer 1

Hi there

Your answer is :-

Sn = Sum of all number

n = Number of terms

a = First number

an = last number




sn = n/2 ( a + an )

sn = 15 /2 ( 1 + 29 )

sn = 15/2 × 30

sn = 15 × 15

sn = 225 ( ans )


Thank You