Question

Calculeaza urmatoarea suma: 2+4+6+....+600

Answer 1

2+4+6+...+600
= 2×1 + 2×2 + 2×3 + ... + 2×300
= 2×(1+2+3+...+300)
$=2\times\frac{300\times301}{2} \\ \\ =\frac{2\times300\times301}{2}$
= 300×301
= 90300