Question
In a gathering of 30 guests, the average age of each
guest in the class is 21 years. Later, 4 more guests join the party, causing the average age of the entire party to decrease by 12 months. Determine the average age of the 4 guests who joined the class.Solution
ATQ, Initial sum of ages of the guest in the party = 21 × 30 = 630 years New average age of the guest = 21 - (12/12) = 21 - 1 = 20 years New sum of ages of the guest in the party = 20 × 34 = 680 years So, the sum of ages of the guest who joined the party = 680 - 630 = 50 years So, the required average = (50/4) = 12.5 years
0.3Ì…2Ì… + 0.54Ì…8Ì… - 0.1Ì…9Ì… is equal to :
A large metallic sphere of radius 21 cm is melted and used to make small cuboidal bars of dimensions 7 cm × 6 cm × 3 cm. Find the number of bars that ...
Each side of square ‘A’ is 5 cm less than that of square ‘B’. The perimeter of a rectangle is 2 times the difference of the perimeters of the tw...
Perimeter of a square field is 120 meters and the area of a rectangular field is 20% more than that of the square field. Find the area (in m2...
If a triangle with base 15 cm has the same area as a circle with radius 15 cm, then the corresponding altitude (in cm) of the triangle is:Â
The lateral surface area of a cube is 400 cm2. The length of a cuboid is 50% more than the side of the cube. The breadth of the cuboid is 12 ...
If a triangle with base 4 cm has the same area as a circle with radius 4 cm, then the corresponding altitude (in cm) of the triangle is:Â
If the angular diameter of the sun is 20, how far from the eye a coin of radius 4.95 cm be kept to hide the sun?
A racetrack is in the shape of a rectangle with length of 48 meters and area of 6000 m 2. A car takes 10 seconds to make one lap around the ...
The area of a circle is 1.54 cm2. Find the perimeter of the minor sector that is subtended by an angle of 90o. (take π = 22/7)
Relevant for Exams:
