The average of six numbers is 4. The average of two of them is 3.5, while the average of the other two is 3.75. What is the average of the remaining two numbers?

Total sum of all six numbers = $6\times 4=24$ Sum of the first two numbers = $2\times 3.5=7$ Sum of the next two numbers = $2\times 3.75=7.5$ Sum of these four numbers = $7+7.5=14.5$ Sum of the remaining two numbers = $24-14.5=9.5$ Average of the remaining two numbers = $\frac{9.5}{2}=4.75$