In ΔABC, the medians AD and BE meet at G. The ratio of the areas of ΔBDG and the quadrilateral GDCE is:
1 : 2
1 : 3
2 : 3
3 : 4
Shashi can do a piece of work in 20 days. Tanya is 25% more efficient than Shashi. The number of days taken by Tanya to do the same piece of work is:
15
16
18
25
XYZ is a right angled triangle and ∠Y = 90°. If XY = 2.5 cm and YZ = 6 cm, then the circumradius of Δ XYZ is:
6.5 cm
3.25 cm
3 cm
2.5 cm
B.
3.25 cm
In Δ XYZ,
(XZ)2 = (XY)2 + (YZ)2
(XZ)2 = (2.5)2 + (6)2
(XZ)2 = 6.25 + 36
(XZ)2 = 42.25
XZ = 6.5 cm
∴ Circum-radius of Δ XYZ
The length of shadow of a tower is √3 times that of its length. The angle of elevation of the sun is
45°
30°
60°
None of these
If x is the area, y is the circumference and z is the diameter of circle then the value of is
4 : 1
1 : 4
1 : 2
2 : 1