if that was on my plan it would mean this:

total time 1:30
warm up for about 20-30 minutes
do 3 10-minute intervals at zone 3 with 2 minutes easy in between. - that is 36 minutes.
or said another way ( 10 minutes at zone 3, 2 minutes at zone easy ) repeat 3 times
cool down for 20-30 minutes.