บท 638: Winning Money (1)

The Sixth Princess followed Lin Xiaoyue's calculations and nodded as she listened and watched.

"This formula is valid for the sum of all arithmetic progression. You can come up with your own questions now and try to solve them." Lin Xiaoyue said.

The Sixth Princess glanced at Lin Xiaoyue, half-believing.

Then, she picked up the brush and began to calculate.

After calculating several questions in a row, she found it was indeed the same as what Lin Xiaoyue had said. The Sixth Princess was shocked and impressed.

Lin Xiaoyue waited until the Sixth Princess stopped writing before she continued. "Besides this formula, there's another one."

"What other formulas are there?" The Sixth Princess was immediately interested.