---
id: 5e9a0a8e09c5df3cc3600ed4
title: 'Accessing and Changing Elements, Rows, Columns'
challengeType: 11
videoId: v-7Y7koJ_N0
# --question--
## --text--
What code would change the values in the 3rd column of both of the following Numpy arrays to 20?
```py
a = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]])
# Output:
# [[ 1 2 20 4 5]
# [ 6 7 20 9 10]]
```
## --answers--
```python
a[:, 3] = 20
a[2, :] = 20
a[:, 2] = 20
a[1, 2] = 20
## --video-solution--
3