In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: from an island , it is possible to reach the mainland by either ferry p or ferry q . ferry p travels for 3 hours at 6 kilometers per hour , while ferry q takes a route that is three times longer . if ferry p is slower than ferry q by 3 kilometers per hour , how many hours longer is the journey of ferry q compared with the journey of ferry p ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5
[EX A]: c

[EX Q]: Problem: today mary ’ s father is 4 times as old as mary . 3 years ago , he was 5 times as old . how old is mary today ? 
Options: a ) 6 , b ) 8 , c ) 10 , d ) 12 , e ) 14
[EX A]: d

[EX Q]: Problem: a is 1.5 times as fast as b . a alone can do the work in 30 days . if a and b work on alternative days , beginning with a , in how many days will the work be completed ? 
Options: a ) 23 , b ) 22 , c ) 21 , d ) 36 , e ) 25
[EX A]:
d