Tina can do a job in 12 hrs

thus in 1 hr tina will do 1/12th job

in 8 hrs tina can do 1/12 * 8= 3/4

thus 1/4th job is remaining

ann can do a job in 9 hrs

thus

she can do 1/4th job in 9*1/4 = 2.25 hrs=2 hrs 15 min

thus in 1 hr tina will do 1/12th job

in 8 hrs tina can do 1/12 * 8= 3/4

thus 1/4th job is remaining

ann can do a job in 9 hrs

thus

she can do 1/4th job in 9*1/4 = 2.25 hrs=2 hrs 15 min