a monkey ascends a greased pole 20 metres high . he ascends 2 metres in first minute and slips down 1 metre in the alternate minute . in which minute , he reaches the top ?
"in 2 minutes , he ascends = 1 metre â ˆ ´ 18 metres , he ascends in 36 minutes . â ˆ ´ he reaches the top in 37 th minute . answer e"
subtract(multiply(2, 20), 1)