What painting will the artist hang on the wall at 9:20?

Question

In the Art Gallery is a new conceptual art piece. The artist created a huge pile different paintings; periodically he picks up one of the paintings and hangs it on the wall, and adjusts it.
At 11:00, the painting titled "Number 30" was hung.
At 4:00, the painting titled "Number 240" was hung.
At 7:30, the painting titled "Number 315" was hung.

What painting will the artist hang on the wall at 9:20?

Answer 1

Answer is 200
Formula for calculating angle between hour hand and minute hand
Angle = [1/2*(60*Hr + Minutes)]-(6*Minutes)
At 11.00
Angle = [0.5*( 60*11 + 0)]-(6*0) = 330
So number of painting = 360-330 =30
At 4.00
Angle = 120
So no. of painting = 360-120 = 240
Similarly for 7.30, angle = 45
so no. of painting = 360-45 = 315
Now at 9.20
Angle = [0.5*(60*9 + 20)] - (6*20) = 160
So painting number will be = 360-160 =200