**751. A can complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km / hr and second half at the rate of 24 km / hr. Find the total journey in km.**

A. 220 km**B. 224 km**

C. 230 km

D. 234 km

**752. A car is running at a speed of 108 kmph. What distance will it cover in 15 seconds ?**

A. 45 metres

B. 55 metres**C. 450 metres**

D. Cannot be determined

**753. A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km /hr, the time taken by it to cover the same distance will be :__________?**

A. 10 min

B. 11 min 20 sec

C. 13 min**D. 13 min 20 sec**

**Explanation:****Speed = (10 X 60/12 ) km/hr = 50 km/hr. New speed = (50 – 5) km / hr = 45 km /hr. So Time taken = ( 10/45 ) hr = ( 2/9X 60 )min 131/3 min = 13 min 20 sec.**

**Explanation:****Volume of water displaced = (3 X 2 X 0.01) m3 = 0.06 m3.****Mass of man = Volume of water displaced X Density of water****= (0.06 X 1000) kg = 60 kg.**

**754. The radius of the cylinder is half its height and area of the inner part is 616 sq. cms. Approximately how many litres of milk can it contain ?**

A. 1.4**B. 1.5**

C. 1.7

D. 1.9

**755. The capacity of a cylindrical tank is 246.4 litres. If the height is 4 metres, what is the diameter of the base ?**

A. 1.4 m

B. 2.8 m

C. 14 m**D. None of these**

**756. A boat having a length 3 m and breadth 2 m is floating on a lake The boat sinks by 1 cm when a man gets on it. The mass of man is :__________?**

A. 12 kg**B. 60 kg**

C. 72 kg

D. 96 kg

**757. The areas of the three adjacent faces of a rectangular box which meet in a point are known. The product of these areas is equal to :___________?**

A. the volume of the box

B. twice the volume of the box**C. the square of the volume of the box**

D. the cube root of the volume of the box

**Explanation:****Let length = 1, breadth = b and height = h. Then,****Product of areas of 3 adjacent faces = (lb x bh x 1h) = (lbh)2 = (Volume)2.**

**758. The edges of a cuboid are in the ratio 1 : 2 : 3 and its sun face area is 88 cm2. The volume of the cuboid is :_________?**

A. 24 cm3**B. 48 cm3**

C. 64 cm3

D. 120 cm3

**Explanation:****Let the dimensions of the cuboid be x, 2x and 3x.****Then, 2 (x X 2x + 2x X 3x + x X 3x) = 88****⇔ 2X2 6X2 + 3X2 = 44 ⇔ 11X2 = 44 ⇔ X2 = 4 ⇔ x = 2.****Volume of the Cuboid = (2 X 4 X 6) cm3 = 48 cm3.**

**759. What is the volume of a cube (in cubic cm) whose diagonal measures 4√3 cm ?**

A. 8

B. 16

C. 27**D. 64**

**760. A cuboidal, block of 6 cm X 9 cm X 12 cm is cut up into an exact number of equal cubes. The least possible number of cubes will be_________?**

A. 6

B. 9**C. 24**

D. 30

**Explanation:****Volume of block = (6 X 9 X 12) cm3 = 648 cm3.****Side of largest cube = H.C.F. of 6 cm, 9 cm, 12 cm = 3 cm.****Volume of this cube = (3 X 3 X 3) = 27 cm3.****Number of cubes = 648/27 = 24.**