Pria's radio produces 80 useful energy units for every 100 units of electricity used. the efficiency of the radio is 0.80 percent 20 percent 80 percent 100 percent

The efficiency of the radio is 80 percent.

80 useful energy units

100 units of electricity used

80 ÷ 100 =  0,8 × 100 = 80%

the answer is true!                                          

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.