73,127,849 rounded to the nearest ten

The next larger ten is . . . . . . 50 .
The next smaller ten is . . . . . . 40 .

. . . . . . 49  is closer to . . . . . . 50  than it is to . . . . . . 40 .

So the nearest ten is . . . . . . 50 .

73127850, I think, usually you round with decimals but yeah

Well if you have 20 bats you probably want 20 balls? you don’t have enough context to answer the question.