The daily pocket money (in ₹) of 40 students was recorded as follows (class intervals are inclusive):
| Pocket money (₹) | Number of students |
| 40–49 | 3 |
| 50–59 | 7 |
| 60–69 | 18 |
| 70–79 | 10 |
| 80–89 | 2 |
Calculate the median pocket money.