We know that,
⇒Mean=∑fixi∑fi
Now,
Class mark(xi)Frequency(fi)(xifi)3012360401664050p50p60159007085608019152090131170
So,
⇒∑fi=83+p
⇒∑fixi=5150+50p
Now,
⇒∑fixi∑fi=Mean
⇒5150+50p83+p=60
⇒5150+50p=4980+60p
⇒170=10p
⇒p=17
Hence, the value of p is 17.