The Total solution for NCERT class 6-12
Given,N = 90∴ N/2 = 90/2 =45Which lies in the interval 50-60Lower limit, l = 50, f= 20, cf= 40 + p, h = 10∴ P = 5Also, 78 +p + q = 90⇒ 78 + 5+ q = 90⇒ q =90-83∴ q = 7