A bag contains 8 red balls and some white balls. If the probability of drawing a white ball is half of the probability of drawing a red ball then find the probability of drawing a red ball and a white ball if the balls are drawn without replacement.

The ages of students in a small primary school were recorded in the table below.

Estimate the median.

Find the matrix A

A \(\begin {bmatrix} 0 & 1\\2 & -1 \end {bmatrix}\) = \(\begin {bmatrix} 2 & -1\\1 & 0 \end {bmatrix}\)

How many students scored at least 25%

If \(-2x^3 + 6x^2 + 17x\) - 21 is divided by \((x + 1)\), then the remainder is