4.Three spherical balls of radii 1 cm, 2 cm and 3 cm are melted to form a single spherical ball. In the process, the loss of materials is 25%. The radius of the new ball is .
(1)6 cm
(2)5 cm
(3)3 cm
(4)2 cm
5.Three horses are tethered at 3 corners of a triangular plot of land having sides 20 m, 30 m and 40 m each with a rope of length 7 m. The area (in m^2) of the region of this plot, which can be grazed by the horses, is (Use π=22/7)
(1)77/3
(2) 75
(3) 77
(4)80
6.A wire, when bent in the form of a square, encloses a region of area 121 cm^2. If the same wire is bent into the form of a circle,then the area of the circle is(Use π=22/7)
(1) 150 cm^2
(2) 152 cm^2
(3) 154 cm^2
(4) 159 cm^2
9.The sides of a right - angled triangle forming right angle are in the ratio 5:12. If the area of the triangle is 270 cm^2, then the length of the hypotenuse is
(a) 39 cm
(b) 42 cm
(c) 45 cm
(d) 51 cm
10.If the radius of a sphere is increased by 2 m, its surface- area is increased by 704 m^2. What is the radius of the original sphere? (Use π=22/7)
(a) 16 m
(b) 15 m
(c) 14 m
(d) 13 m
Answers and Solution:
No comments:
Post a Comment