Answer:
$70
Explanation:
To add a tip, we must multiply the cost of the bill by 1.15. This will give us the total amount including the tip.
57.86 x 1.15 = 66.539
Because this is money, and it wants us to round to the nearest ten dollars, the cost would be $70. (66.539 is closer to 70 than it is to 60)