In a sale, the normal price of a book is reduced by 20%. The sale price of the book is £4.80
Work out the normal price of the book

Write the system of equations represented by the matrix. 0 1 2 4 -2 3 6 9 1 0 1 3

Twelve less than a number is at most 20

Aclassroom is made up of 11 boys and 14 girls. the teacher has four main classroom responsibilities that she wants to hand out to four different students (one for each of the four students). if the teacher chooses 4 of the students at random, then what is the probability that the four students chosen to complete the responsibilities will be all boys?