60. Find area of a rectangle.
A. Length and breadth of the rectangle are in the ratio of 4:3.
B. Sum of the lengths of diagonals of the rectangle is 50 m.
C. Area of a square is 1225 m², whose perimeter is twice the perimeter of the rectangle.
A → Let the length and breadth of the rectancle be 4x and 3x respectively.
B→ Sum of the lengths of diagonals of the rectangle = 50m
Rectangle's diagonals are always equal. ⇒ d= 25m = √ length^2 + Breadth ^2
C → Area of a square = 1225 m^2
Edge of the square = 35m
Perimeter of the square = 4 ×35 = 140m
Perimeter of the rectangle = 1 ÷ 2 × Perimeter of the square = 70m = 2 (Length + Breadth)
Hence, the questions can be answered by using any two of three statements together.
A → Train A crosses another train B moving in the opposite direction in 10 sec.
∴ Time taken = 10 sec B→ Ratio of the speeds of trains A and B = 1:2
∴Let the speeds of trains A and B be x and 2x m/sec respectively.
C→ Length of train B is 25% more than that of train A.
∴ Let the lengths of trains A and B be 4y and 5y meters respectively.
From all the three statement
Relative speed = x + 2 x = 3x
Sum of lengths of train = 4 y + 5 y = 9y
Time taken = sum of lengths of trains ÷ Relative speed
⇒ 10 = 9y ÷ 3 x
Hence, the question cannot be answered even by using all the three statements together.
A → Let the length and breadth of the rectancle be 4x and 3x respectively.
B→ Sum of the lengths of diagonals of the rectangle = 50m
Rectangle's diagonals are always equal. ⇒ d= 25m = √ length^2 + Breadth ^2
C → Area of a square = 1225 m^2
Edge of the square = 35m
Perimeter of the square = 4 ×35 = 140m
Perimeter of the rectangle = 1 ÷ 2 × Perimeter of the square = 70m = 2 (Length + Breadth)
Hence, the questions can be answered by using any two of three statements together.