The following series relates to the daily income of workers employed in a firm. Compute:
(a) Highest income of lowest 50% workers
(b) Minimum income earned by top 25% workers
(c) Maximum income earned by lowest 25% workers.

Daily Income (Rs.)	Number of workers
10 – 14	5
15 – 19	10
20 – 24	15
25 – 29	20
30 – 34	10
35 – 39	5