Q$1.$ Consider a relation s$($A$,$B$)$ with the following characteristics:$$ s has $700,000$ tuples with $70$ tuples per disk block$$ s has an index on attribute A with index height x$=2($i$.$e$.,$ the index has nodes on $3$ levels$)$ The values that the attribute A takes in relation s are integers which are uniformly distributed in the range $1...200.[$Uniformly distributed $$ there are roughly $3500$ tuples for each A value.$](1.$a$)$ Assuming that the index on A is a secondary index, estimate the number of disk block accesses needed to compute the query $\backslash$sigma A$=18($s$).$