Question
The length of sides of a square is twice the radius of a
circle and perimeter of a rectangle is half the perimeter of the square. If the sum of length and breadth of rectangle is 24 cm, then find the area of the circle (in cm2). [Take π = 2]Solution
Let the length of a square be ‘a’. And the radius of a circle be ‘r’. Now, a = 2r ----- (i) Perimeter of the rectangle = 1/2 × 4a = 2a => 2(l + b) = 2a => 2 × 24 = 2a => a = 24 cm Putting value of ‘a’ in (i) we get, Radius = r = 24/2 = 12 cm Area of the circle = πr2 = 2 × 12 × 12 = 288 cm2.
- The ratio of pens to pencils in a shop is 8:5. If 24 pens are sold and 21 pencils are added, the number of pens and pencils becomes equal. Find the origina...
- If 72% of (P - Q) is equal to 30% of 60% of (P + Q), then find the value of Q:P.
- Kiran shared 288 toffees among his three friends Sonu, Monu and Tanu in the ratio 2:3:7 respectively. Find how many more toffees Tanu received than Sonu.
The entry ticket at a fun park was increased in the ratio 7 : 9, due to which footfalls fell in the ratio 13 : 11. What is the new daily collection (in ...
The incomes of two colleagues 'X' and 'Y' are in the ratio 6:11. 'X' spends 70% of his income, while 'Y' spends 72.72% of his income. Find the ratio of ...
Ratio of cats to dogs in a shelter is 4:3. If 16 cats are adopted and 20 more dogs arrive, their numbers become the same. What was the initial number of...
Amit had 650 pens. He gave 40% of them to Suman and Rishi in the ratio 3:2. Find the difference between the number of pens left with Amit and the number...
- In a classroom, the ratio of the number of left-handed to right-handed students is 5:6. When 10 more students of each type join, the ratio changes to 15:16...
The radii of two solid right circular cylinders are 6 cm and 4 cm respectively and their heights are (h+1) cm and (2h+1) cm respectively. If the areas o...
