49) A man spends 15% of his income on agriculture, 21% on family and 24% on education of children. If he saves Rs 360, find out the total income.

50) If (y+2)(y-3)=(y-6)(y+9)+8, find the value of y.

51) Find the area of equilateral triangle, if its side is 10 cm.

52) A hollow shaft has 375 mm outside diameter and 275 mm inside diameter. The area of cross section is equal to

53) What is the percentage of copper and tin in bell metal?