Time in DDD Reports can get… odd… so here is the formula to get it in Hours:
Duration Including Travel Time
NUMBERVALUE([Duration])+NUMBERVALUE(LEFT(RIGHT(TEXT([Duration]),5),2))/60
Duration without Travel Time
(NUMBERVALUE([Duration])+NUMBERVALUE(LEFT(RIGHT(TEXT([Duration]),5),2))/60) - (NUMBERVALUE([Travel Time])+NUMBERVALUE(LEFT(RIGHT(TEXT([Travel Time]),5),2))/60)