SOLVE
LATER
Shiva is planning to watch movie Dangal with his friends (total M people). They all decide and choose row D of PVR (row D has total N seats) but each one of them books his own ticket individually. Every pair of friends sitting together orders one pack of popcorn. Each pack costs Rs 50. Find the expected amount W that Shiva and his friends will spend on popcorn.
First line contains a single integer T denoting the number of test cases. T lines follow, each containing two integers N and M.
Output the greatest integer less than or equal to W for each test case in separate lines.
T <=100
1<=M<=N<=1000000
There are 3 friends and 3 seats and thus only one way in which they can be seated and there are 2 pairs of friends sitting together and thus, buy 2 packs of popcorn.