Question
The average of six numbers is 8. When three new numbers
are included in such a way that the first number is  twice the second and second number is thrice the third, now the average of nine numbers becomes 12. What will be the difference of first and third among the new numbers?ÂSolution
Sum of five numbers = 6 × 8 = 48 Let the third number be x, Second number will be 3x, First number will be 6x According to the question, (48+6x+3x+x)/9=12 ;  (48+10x)/9=12; x=  (108-48)/10 x=6 ∴ the three numbers will be 6, 18 and 36 ∴ Difference of first and third no.= 36 – 6 = 30
What is the perimeter of the square inscribed in a circle of radius 8 cm?
A cone has a height of 28 cm. A sphere is melted to form this cone. If the radius of the sphere is 7 cm, find the radius of the base of the cone.
Find out the diameter of the incircle of a given triangle with a semi-perimeter of 24 cm and an area of 72 cm².
A sphere is cut into hemisphere. One of them is used as bowl. It takes 8 bowlfuls of this to fill a conical vessel of height 12cm and radius 6cm. Then f...
The length of a rectangle, area of which is 168 cm2, is equal to the radius of a circle of area 616 cm2. Find the perimeter of the...
A rectangle is 14 cm long and 10 cm wide. A semicircle is attached on the 14 cm side (diameter = 14 cm). Find total area. (Take π = 22/7)
If the curved surface area and the radius of a cylinder are 550 cm2 and 7 cm, respectively, then find the volume (in cm3) of the c...
The side of a square is equal to the diameter of a circle. The area of a square is 196 sq cm. what is the area of the circle?
If the length of the diagonal of a square is 9.2 cm, then the area of the square is:
Length and breadth of a rectangle are in the ratio 2:7. If the perimeter of the rectangle is 44 cm more than the length of the rectangle, then find the ...
Relevant for Exams:
