Answer: Overtone number=pattern number-1
Explanation: An overtone is any frequency greater than the fundamental frequency( the lowest frequency of periodic waveform) overtone is equal to standing wave pattern minus 1.
Standing wave pattern can be described as a vibrational wave pattern formed inside a medium when the vibrational frequency of the source forms reflected waves from one end of the medium to interfere with incident waves from the source. Both terms are used when describing sound waves created in musical instruments like GUITAR etc