Question

one the planet oz, there are 8 days in a week ? sunday to saturday and another day called oz day. there are 36 hours in a day and each hour has 90 minutes while each minute has 60 seconds. as on earth, the hour hand covers the dial twice every day. find the approximate angle between the hands of clock on oz when the time is 12.40 am. (a) 89 (b) 251 (c) 111 (d) 79

Answer 1

The answer to this is option A: 89

36hrs a day mane the clk will b of 18hrs.

18hrs covers 360 deg

Thus 1hr covers 20  deg

12 hrs covers 12*20=240 deg

1 hr in 90min

Thus in 90 min the hour hand goes 20 deg

For 1min hr hand goes 2/9deg

For 40 min hour  goes (2/9)*40 deg=80/9 deg=9 deg (approx)

thus hr hand covers total of 240+9=249 deg

now min hand covers=40*4=160 deg

(90min=360deg

1min=4deg)

Thus angle between them 249-160 = 89 deg

Answer 2

See the attachment for full concept.

I think it will be helpful for clearing doughts.