Khaike paan banaraswala ? - Android piano with drums #shorts #music

Two musical notes of the same pitch and loudness are played on a violin and a piano. The wave forms are as shown in the figures given below. Explain why the wave patterns are differnt.

In a class of 40 students, 24 like to play guitar and 25 like to play piano. If each students like at least one of the musical instrutment, then how many like to play both piano and guitar?