Question

Some pupils in two different classes take a test. There are 15 pupils in 10X1 and 24 pupils in 10Y1. The mean mark for the pupils in 10X1 is 26. The mean mark for the pupils in the two classes combined is 10. Calculate the mean mark for the pupils in 10Y1. (correct to 2DP)​

Answer 1

To calculate the mean mark for the pupils in 10Y1, we can use the formula for calculating the mean mark for a class which is:

• Mean mark = (Total marks for all pupils in a class) / (Number of pupils in that class)

We know that there are 15 pupils in 10X1 and their mean mark is 26. We also know that there are 24 pupils in 10Y1 and the mean mark for both classes combined is 10.

Let's first calculate the total marks for all pupils in both classes combined:

• Total marks = Mean mark x Number of pupils
• Total marks = Mean mark x Number of pupilsTotal marks = 10 x (15 + 24)
• Total marks = Mean mark x Number of pupilsTotal marks = 10 x (15 + 24)Total marks = 390

Now we can calculate the total marks for all pupils in 10Y1:

• Total marks for 10Y1 = Total marks - Total marks for 10X1
• Total marks for 10Y1 = 390 - (15 x 26)
• Total marks for 10Y1 = 390 - 390
• Total marks for 10Y1 = 0

Therefore, the mean mark for the pupils in 10Y1 is **0** (correct to two decimal places).