A car covers four successive 7km distances at speeds of 10 km/hour, 20 km/hour, 30 km/hour and 60 km/hour respectively. Its average speed over this distance is
30 km/hour
20 km/hour
60 km/hour
60 km/hour
If 64 buckets of water are removed from a cubical shaped water tank completely filled with water,  of the tank remains filled with water. The length of each side of the tank is 1.2 m. Assuming that all buckets are of the same measure, then the volume (in litres) of water contained by each bucket is
12
16
15
15
The centroid of a Δ ABC is G. The area of Δ ABC is 60 cm2. The area of ΔGBC is
10 cm2
30 cm2
40 cm2
40 cm2
The base of a right pyramid is a square side 10 cm. If the height of the pyramid is 12 cm, then its total surface area is
400 cm2
460 cm2
260 cm2
260 cm2
60 kg of an alloy A is mixed with 100 kg of alloy B. If alloy A has lead and tin in the ratio 3 : 2 and alloy B has tin and copper in the ratio 1 : 4, the amount of tin in the new alloy is
53 kg
44 kg
80 kg
80 kg
In trapezium ABCD, AB || CD and AB = 2CD. Its diagonals intersect at O. If the area of ΔAOB = 84 cm2, then the area of ΔCOD is equal to
72 cm2
21 cm2
42 cm2
42 cm2
Quadrilateral ABCD is circumscribed about a circle. If the lengths of AB, BC and CD are 7 cm, 8.5 cm and 9.2 cm respectively, then the length ( in cm) of DA is
7.7
16.2
10.7
10.7
A.
7.7
In a school there were 1554 students and the ratio of the number of the boys and girls was 4 : 3. After a few days, 30 girls joined the school but a few boys left; as a result the ratio of the boys and girls became 7 : 6. The number of boys who left the school is
76
74
84
84