A helicopter blade does 3206 full turns in 7 minutes. Work out the number of full turns per minute? Then work out how many turns the 30 minute flight takes thereafter.

458 turns/min 13740/30 min

Step-by-step explanation:

3206/7 (min) = 458

458 x 30 (min) = 13740

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47