Question
Solution
Let the speed of B be x kmph ⇒ Time taken by B to cover 40 km = 40/x ⇒ Time taken by A = (40/x) + 2 So, the speed of A = (20x)/(20 + x)   ----(1) Distance = 80 km ⇒ Time taken by B to cover 80 km = 80/x   ----(2) ⇒ Speed of A when he doubles his speed = (40x)/(20 + x) ⇒ Time taken by A to cover 80 km = (40 + 2x)/(x)   ----(3) A.T.Q., From (2) and (3) (80/x) + (3/2) = (40 + 2x)/x ⇒ (40 + 2x)/2x - 80/x = 3/2 ⇒ 2 (40 + 2x - 80) = 3x ⇒ 2 (2x - 40) = 3x ⇒ 4x - 80 = 3x ⇒ 4x - 3x = 80 ⇒ x = 80 ⇒ Speed of B = 80 kmph Distance = 90 km Time taken by B = 90/80 = 1(1/8) hrs
In a circle of radius 13 cm, a chord is of length 10 cm. Find the distance of the chord from the centre.
From an external point P, two tangents PA and PB are drawn to a circle with centre O and radius 5 cm. The angle between the tangents ∠APB is 60°. Fin...
In a circle of radius 10 cm, a chord AB has length 10√3 cm. Find:
(i) the distance of the chord from the centre, and
(ii) the measure of...
Sum of diameter and circumference of a circle is 232 cm, the find area of circle.
In a circle AB is diameter & C is a point on circumference such that AC = 8 cm & BC = 15 cm then find the area of circle ?
Two chords AB and CD of a circle intersect at E such that AE = 3.4 cm, BE = 4.2 cm and CE = 2.6 cm. What is the approximate length of DE?
- A rhombus has an area of 1,800 cm², and its diagonals are in the ratio 6:5. A circle is drawn using the smaller diagonal as its diameter. What is the diff...
- The diagonals of a rhombus are in the ratio 7:5, and its area is 3,500 cm². A circle is formed taking the smaller diagonal as the diameter. Find the diffe...
The circumference of a circle equals the perimeter of a square of side 14. Find area of circle.
- In a circular field, the area is six times its circumference in terms of numerical value. Calculate the diameter of the field.