Customers at an ice cream shop took a survey. There is also 90 customers rated the shop as excellent. If this represented 75% of the customers, how many took the survey in total?

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)