Three numbers are in the ratio 3 : 4 : 5. The sum of the largest and the smallest equals the sum of the second and 52. The smallest number is
20
27
39
52
If the radius of a circle is increased by 50%, its area is increased by
125%
100%
75%
50%
A and B working separately can do a piece of work in 9 and 12 days respectively. If they work for a day alternately with A beginning, the work would be completed in
A and B together can do a work in 10 days. B and C together can do the same work in 6 days. A and C together can do the work in 12 days. Then A, B and C together can do the work in
28 days
14 days
A does half as much work as B in three-fourth of the time. If together they take 18 days to complete a work, how much time shall B take to do it alone?
30 days
35 days
40 days
45 days
If a wire is bent into the shape of a square, then the area of the square so formed 81 cm2. When the wire is rebent into semicircular shape, then the area (in cm2) of the semi-circle will be
22
44
77
154
Marbles of diameter 1.4 cm are dropped into a cylindrical beaker containing some water and are fully submerged. The diameter of the beaker is 7 cm. Find how many marbles have been dropped in it, if the water rises by 5.6 cm.
50
150
250
350
Water is flowing at the rate of 3 km/h through a circular pipe of 20 cm internal diameter into a circular cistern of diameter 10 m and depth 2 m. In how much time will the cistern be filled?
1 h
1 h 40 min
1 h 20 min
2 h 40 min
B.
1 h 40 min
Volume of water flows through pipe in 1 hour is given by,
Volume of circular cistern is given by,
∴ Required time to fill up the cistern