Ken saves $140 per month. if this is 2.5% of his monthly income, how much does he earn per month ?

$140 = 2,5%
$140 = 5/2%
1% = $140 . 2/5
1% = $56
100% = $5600

Time taken by Diana to finish her project is 5 1/3 hours
Gabe took 1 1/4 times as long as Diana, therefore Gabes time will be:
1 1/4 × 5 1/3
=5/4 × 16/3
=20/3
=6 2/3 hours

Paula took 3/4 times as long as Diana, therefore time taken by Paula will be:
3/4 × 16/3
=4 hours

- Hope this helps :)