Determine the total time cannon ball was above the height of the tower

What is the size of the matrix resulting from

See attachment below and find the equivalent of tan(∠qsr)

Afactory buys 10% of its components from suppliers b and the rest from supplier c. it is known that 6% of the components it buys are faulty. of the components brought from suppliers a,9% are faulty and of the components bought from suppliers b, 3% are faulty. find the percentage of components bought from supplier c that are faulty.