A group of pupils volunteered at an old folks' home for 5 days. The line graph shows their attendance at the old folks' home from Monday to Friday. All pupils turned up on Friday. On which day were 30% of the pupils absent from the old folks' home? Ans: ___

1. Determine the total number of pupils in the group.

Since all pupils turned up on Friday, the total number of pupils is the attendance on Friday.
From the graph, the attendance on Friday is $60$.

2. Calculate the number of pupils present when 30% are absent.

If $30\%$ are absent, then $100\% - 30\% = 70\%$ are present.
Number of pupils present = $70\% \times 60 = \frac{70}{100} \times 60 = 42$.

3. Identify the day with this attendance from the graph.

Looking at the graph, the attendance was $42$ on Thursday.