Pls help with these i only have 20 mins

QUESTION 1 At a distance of 5 m away from a loud machine, the sound level measures 85.13 dB. What is the sound level at 15 m from the machine? Assume that the sound comes out of the machine equally in every direction. Enter your answer in dB rounded to two decimal places. QUESTION 2 555-nm light passes through two slits and produces an interference pattern on a far-away screen. The first bright fringes are measured to be 0.3 mm to either side of the central maximum. Then, a different monochromatic light of unknown wavelength is used to generate an interference pattern using the same equipment. This time, the second bright fringes are measured to be 0.8 mm to either side of the central maximum. Find the unknown wavelength of the second light. Report your answer in nm rounded to zero decimal places. Don't type in the units. Hint: Since the screen is very far away, the angles involved are very small. Thus you may assume that tand ~ sine = 0. QUESTION 3 A smartphone broadcasts a signal to a local cell tower at 2.2 GHz. What is the wavelength of this signal? Report your answer in meters rounded to two decimal places. Don't type in the units