Question

calculati(3+6+9+ ...+300):(1+2+3+ ...+100)

Answer 1

=3(1+2+3+....100):(1+2+3+...100)=3

Answer 2

3+6+9+...+300
3×1+3×2+3×3+...+3×100
3×(1+2+3+...+100)
3×(100×101:2)
3×(50×101)
3×5050=15150

100×101:2
50×101=5050

15150:5050=3
R:3