Let base = b and altitude = h Then, Area = b x h But New base = 110b / 100 = 11b / 10Let New altitude = HThen, Decrese = (h - 10h /11 )= h / 11? Required decrease per cent = (h/11) x (1 / h ) x 100 %= 91/11 %
Let Length = 5y meters and breadth = 3y meters.Then, perimeter = 2 x (5y + 3y ) m = 16y meters ...(i)But perimeter = Total Cost / Rate = 3000 / 7.50 m = 400 m ...(ii)from eqs. (i) and (ii)16y = 400? y = 25? Length - Breadth = (5 x 25 - 3 x 25 ) m = 2 x 25 m = 50 m
Area of the field =1215/135 = 9 hec= 90000 m2 [1 hec =10000 m2]? Side of the field = ?90000 = 300 mPerimeter of the field = 4 x 300 = 1200 mNow, cost of putting a fence around field = (1200 x 75)/100 = ? 900
In a triangleSum of two sides is always greater than 3rd side i.e., x < 25 + 15 = 40 .....(i)Difference of two sides is always less than 3rd side i.e., 25 - 15 = 10 < x ...(ii) From Eqs. (i) and (ii) , we get 10 < x < 40