Question
A, B, and C each have different rates of completing a
task; A can finish it in 36 days, B in 60 days, and C in 30 days. Initially, they begin the work collaboratively, but C departs after 5 days. Furthermore, A exits the job 18 days before the final completion. How long does it take to complete the entire task?Solution
Let the total work = 180 units (LCM of 36, 60 and 30) Amount of work done by A alone in one day = 180/36 = 5 units Amount of work done by B alone in one day = 180/60 = 3 units Amount of work done by C alone in one day = 180/30 = 6 units Amount of work done by A, B and C together in 5 days = 5 × (5 + 3 + 6) = 70 units Amount of work done by B alone in 18 days = 18 × 3 = 54 units Remaining work = 180 – 70 – 54 = 56 units Time taken by A and B together to complete 56 units work = 56/(5 + 3) = 7 days So the total time taken to complete the work = 5 + 18 + 7 = 30 days
Find the area of the sector of a circle with radius 14 cm and central angle 90°.
- Calculate the area of a circle whose radius is (7/8)ᵗʰ of the side of a square whose area measures 1,600 cm². (Take π = 3.14)
- A rhombus has an area of 2,592 cm² and its diagonals are in the ratio 5:3. A circle is drawn with the shorter diagonal of the rhombus as its diameter. Cal...
The radius of a circle is 7 cm. Find the area of the sector formed by a central angle of 90°.
- A circular sector has a radius of 14 cm and an area of 154 cm². What is the angle formed at the center by the arc? (Take π = 22/7)
The circumference of a wheel is 39.6 cm. What is the radius of the wheel?
- The numerical value of the area of a circular park is ten times the numerical value of its perimeter. Find the diameter of the park.
The area of a sector of a circle is 88cm² and the angle of the sector is 60º. Find the radius of the 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?
In a circle, the length of a chord AB is 48 cm & radius is 25 cm. Find the distance between centre and chord.