Which type of electromagnetic radiation has a longer wavelength than visible light

radio waves
On one end of the electromagnetic spectrum are radio waves, which have wavelengths billions of times longer than those of visible light. On the other end of the spectrum are gamma rays, with wavelengths billions of times smaller than those of visible light. Hope it helps

Adozen is 1221/12 = 1.751.75 x 12 = 21therefore, 1.75 is the answer.