To find out the percentage of Tyrone's earnings that he saved, we need to divide the amount he saved by his total earnings and then multiply by 100 to convert the result into a percentage.
The amount that Tyrone saved is $24, and his total earnings are $60.
So,
Percentage of earnings saved = (Amount saved / Total earnings) x 100
= ($24 / $60) x 100
= 0.4 x 100
= 40%
Therefore, Tyrone saved 40% of his earnings by putting aside $24 from the $60 he earned mowing lawns.