Problem of the Day #128: qwetyuiosdfhjklzxvbn (Albert’s Revenge)July 25, 2011

Posted by Seungln in : potd , trackback

Albert is mad at Sreenath for the number of spam messages that Sreenath sent him. As an act of revenge, Albert decides to get back at him with his mashes. He will, however, use a different set of rules in his spamming.

The top row, again, is defined as the row from ‘$q$’ to ‘]’. The home row is from ‘$a$’ to ‘;’, and the bottom row is from ‘$z$’ to ‘.’ (just like problem #121.) Albert will, however, choose four distinct keys in each row instead of two. Albert will type from the top row first, then go to the home row, then go to the bottom row. For each row, Albert will start from the first key to the left and type the keys until he types the second key, skip to the third key and type the keys until he types the fourth key. (That is, if, in the top row, he chooses ‘$q$’, ‘$e$’, ‘$t$’ and ‘$o$’, he will type ‘$qwetyuio$’.)

How many different mashes can Albert spam Sreenath with, if each mash has to have more than $15$ characters?