$1.$ You need to build a B$+$ tree by inserting these values $(71,59,92,85,37,94,33,79,19,40$ and $60)$ in this

order. Each node has $4$ pointers $($n $=4).$ Show a result tree after each value is inserted, and a final tree.

$2.$ Delete $85$ from the tree resulted from $1,$ and show the result as a tree, and explain how you get the result

tree.

$3.$ Delete $71$ from the tree resulted from $1,$ and show the result as a tree, and explain how you get the result

tree.