If the cost of making a leather ball is Rs.431.20 at the rate of Rs.17 – InterviewSolution

InterviewSolution

1.	If the cost of making a leather ball is Rs.431.20 at the rate of Rs.17.50 per square cm. Calculate the length of diameter of the ball.
Answer» Let the radius of the ball =r cm. `therefore` the whole surface area of the ball `=4pir^(2)` sq-cm. Rs. 17.50 is required to make a ball of leather of 1 sq. cm . `therefore ` Rs. 431.20 is requied to make a ball of leather of `(431.20)/(17.50) sq. cm.` `therefore 4 pir^(2) =(431.20)/(17.50)` or ` 4 xx(22)/(7)xxr^(2) =(4312)/(175)` or, `r^(2)=(4312)/(175xx4xx22) =(49)/(25)` or , `r=sqrt((49)/(25))=7/5=1.4` `therefore ` the diameter of the ball `=2xx 1.4 cm =2.8 cm`

Discussion

No Comment Found

Related InterviewSolutions

If the wole surface area of a sphere be 5544 sq-cm, then the volume of the sphere will beA. 38808 ccB. 42304 ccC. 22176 ccD. 33951 cc
`127(2)/(7)` sq. cm of sheet is required to make a hemispherical bowl. Calculate the length of diameter of the forepart of the bowl.
If the cost of making a leather ball is Rs.431.20 at the rate of Rs.17.50 per square cm. Calculate the length of diameter of the ball.
The length of radius of a spherical gas ballon increases from 7 cm to 21 cm as air is being pumped into it, then find the ratio of surface areas of the ballon in two cases .
A large new sphere is made by melting two metal sphere of radii `r_(1) "unit and" r_(2)` unit respectively. Find the radius of the large sphere.
If the length of diameter of a soild sphere is 28 cm and it is completely immersed into the water then calculate the volume of water displaced by the sphere
A circular iron-plate of thickness `(2)/(3)` cm is made by beating an iron-sphere of diameter 4 cm. What will be the radius of the iron-plate?
on the curved surface of the axis of a globe with the length of 14 cm radius, two circular holes area made each of which has the length of radius 0.7 cm.Calculate the area of metal sheet surrounding its curved surface.
If by melting a solid hemisphere be made into a sphere, then what will be the ratio of their radii?
A sphere of greates volume is cut off from a metal hemisphere of radius 6cm. If the cost of 1 cc metal be ₹42, then what will be the cost of the remaining hemisphere?