A tape that records 1 hour and 30 mins on each side moves at 2 1/2 cm a  second through the tape player. How long, in meters, is the tape?

Time taken for each side
= 1 h 30 min
= (1 × 3600 + 30 × 60) sec
= 5400 sec

Moving speed
= 2 and (1/2) cm/sec
= 2.5/100 m/sec
= 0.025 m/sec

Length of the tape
= 0.025 × 5400 m
= 135 m

The tape length=
2.5(90*60)=13500 cm=13500/100=135 m.

1 h x 3600s/ h + 30 min x 60s / min 
= 3600s + 1800s
=5,400s

2 1/2 cm/s  x  m/100cm = 0.025 m/s

length of tape = 5,400s x 0.025 m/s = 135 m answer//

1 hr 30 min = 3600+30*60 = 5400 seconds

(2.5cm/sec)(5400 sec) = 13500 cm = 13500/100 = 135 m

1 hour = 60 minutes = 3600 seconds
1.5 hours = 5400 seconds
5400 x 2.5 = 13500 cm = 135 meters.

If your rate is 2.5 cm per second, we have:

2.5 cm/sec

And we know that there are 1.5 hours of audio content on the tap.  If we multiply them together, we get:

(2.5 cm/sec) (1.5 hr)

We have a nonsense label:  cm-hr/sec

But if we convert hours to seconds, then the sec labels in the numerator and denominator will cancel out:

(2.5 cm/sec) (1.5 hr) (60 min/hr) (60 sec/min)

Now the hr, min, and sec labels all cancel out leaving only the one label left:  cm

Multiply this out:

13500 cm

We are asked to give the answer in meters, so one more conversion:

(13500 cm) (1/100 m/cm) = 135 m