Question

2+4+6+.....+400 suma lui gauss

Answer 1

Dam factor comun pe 2:
S = 2(1 + 2 + 3 + ... + 200) = 2 * 200 * 201 / 2 = 40 200

Answer 2

S=2+4+6+...+400
S=2 × (1+2+3+..+200)
S= 2 ×$\frac{200*201}{2}$
S=2 ×$\frac{40200}{2}$
S=2×20100
S=40200