Basil has five numbered cards. Two of the numbers are hidden. 4 9 9 ? ? 8

The mode of the five numbers is 8.

The mean of the five numbers is 6

c) Work out the two hidden numbers.

The two hidden numbers are 8 and 1.

Step-by-step explanation:

Mean of a data-set:

The mean of a data-set is given by the sum of all its values divided by the number of values.

Mode of a data-set:

The mode of a data-set is the value that appears the most.

In this question:

4, 9, x, y, 8

Mode is 8 means that at least one of them must be 8, so i will say x is 8 and we have:

4, 9, 8, y, 8

The mean of the five numbers is 6

This means that:

The two hidden numbers are 8 and 1.