$1.$ Find the supplier$-$customer pair$($s$)$ with the most expensive $($o$\_$totalprice$)$ order$($s$)$ completed $($i$.$e$.,$ value of o$\_$orderstatus is F$).$ Print the supplier name, the customer name, and the total price.

$2.$ Find how many distinct customers have at least one order supplied exclusively by suppliers from AFRICA.

$3.$ Find the distinct parts $($p$\_$name$)$ ordered by customers from ASIA that are supplied by exactly $3$ suppliers from AFRICA.

$4.$ Find the nation$($s$)$ with the least developed industry, i$.$e$.,$ selling items totaling the smallest amount of money $($l$\_$extendedprice$)$ in $1994($l$\_$shipdate$).$

$5.$ Find the number of customers who had at most three orders in November $1995($o$\_$orderdate$).$

$6.$ Find how many suppliers from PERU supply more than $40$ different parts.

$7.$ Find the total quantity $($l quantity$)$ of line items shipped per month $($l$\_$shipdate$)$ in $1997.$ Hint: check function strftime to extract the month$/$year from a date.

$8.$ Find how many suppliers have less than $50$ distinct orders from customers in EGYPT and JORDAN together.

$9.$ Find how many suppliers supply the least expensive part $($p$\_$retailprice$).$

$10.$ Find the nation$($s$)$ having customers that spend the largest amount of money $($o$\_$totalprice$).$

$11.$ Find the region where customers spend the largest amount of money $($l extendedprice$)$ buying items from suppliers in the same region.

$12.$ Find how many parts are supplied by exactly one supplier from UNITED STATES.

$13.$ Find the nation$($s$)$ with the largest number of customers.

$14.$ Compute, for every country, the value of economic exchange, i$.$e$.,$ the difference between the number of items from suppliers in that country sold to customers in other countries and the number of items bought by local customers from foreign suppliers in $1997($l$\_$shipdate$).$

$15.$ Compute the change in the economic exchange for every country between $1996$ and $1998.$ There should be two columns in the output for every country: $1997$ and $1998.$ Hint: use CASE to select the values in the result.