1. A hemispherical bowl is filled to the brim with a beverage. The contents of the bowl are transferred into a cylindrical vessel whose radius is 50% more than its height. If the diameter is same for both the bowl and the cylinder, the volume of the beverage in the cylindrical vessel, as a per cent age of t he volume i n t he hemispherical bowl, is
A. [latex]66 \frac{2}{3}[/latex] %
B. [latex]78 \frac{1}{2}[/latex] %
C. 100 %
D. more than 100%
Answer - Option C
Explanation -
Volume of hemisphere = [latex] \frac{2}{3} * \pi * {r}^{3}[/latex]
Volume of cylinder = [latex] \frac{2r}{3} * \pi * {r}^{2}[/latex]
Since the two are equal, the percentage is 100%.
2. In the accompanying figure, AB is one of the diameters of the circle and OC is perpendicular to it through the center O. If AC is 7 [latex]\sqrt{2} [/latex] cm, then what is the area of the circle in sq. cm.?
A. 24.5
B. 49
C. 98
D. 154
Answer - Option D
Explanation -
Let OA = OC = radius = r
[latex]O{A}^{2} + O{C}^{2} = A{C}^{2}[/latex]
[latex]{r}^{2} + {r}^{2} = {(7 \sqrt{2})}^{2} [/latex]
[latex]2{r}^{2} = 2 * 49[/latex]
r = 7
i.e, Area of the circle = [latex]\pi {r}^{2} = \frac {22}{7} * 49 = 154 {cm}^{2}[/latex]
3. A wire is in the form of a circle of radius 35 cm. If it is bent into the shape of a rhombus then what is the side of the rhombus?
A. 32 cm
B. 70 cm
C. 55 cm
D. 17 cm
Answer - Option C
Explanation -
Circumference of the circle = 2[latex]\pi[/latex]r = [latex]2 * \frac{22}{7} * 35[/latex] = 200 cm
= Perimeter of the rhombus
i.e, Side of the rhombus = [latex]\frac{220}{4}[/latex] = 55 cm
4. A person wishes to make a 100 sqm rectangular garden. Since he has only 30 m barbed wire for fencing, he fences only three sides letting the house wall act as the fourth side. The width of the garden is
A. 10 m
B. 5 m
C. 50 m
D. 100 m
Answer - Option B
Explanation -
Let width of the garden be x metres
i.e, Length of the garden = [latex]\frac{100}{x}[/latex]
i.e, [latex]\frac{100}{x}[/latex] + x + x = 30
[latex]{x}^{2}[/latex] – 15x + 50 = 0
x = 10, x = 5
x = 10 is omitted, because in that case, the garden will become square which is contrary to what is given
i.e, Width of the garden = 5 metres
5. The weight of a solid cone having diameter 14cm and vertical height 51 cm is ___, if the material of solid cone weighs 10 grams per cube cm.
A. 16.18 kg
B. 17.25 kg
C. 26.18 kg
D. 71.40 kg
Answer - Option C
Explanation -
Volume of the solid cone = [latex]\frac{1}{3} * \pi * {7}^{2} * 51[/latex]
= [latex]\frac{1}{3} * \frac{22}{7} * 49 * 51[/latex] = 2618 [latex]{cm}^{3}[/latex]
i.e, Weight of the solid cone = (2618 * 10) gm.
= [latex]\frac{26180}{1000} kg[/latex] = 26.18 kg
6. In a special racing event , the per son who enclosed the maximum area would be the winner and would get ₹ 100 for every square metre of area covered by him/her. Johnson, who successfully completed the race and was the eventual winner, enclosed the area shown in figure below. What is the prize money won ?
(Note: arc from C to D makes a complete semi-circle).
AB = 3m, BC = 10m, CD = BE = 2m.
A. ₹ 2914
B. ₹ 2457
C. ₹ 2614
D. ₹ 2500
Answer - Option B
Explanation -
Area of the semi-circle = [latex]\frac{\pi}{2}[/latex] = 1.571 sq. m.
Area of the triangle = [latex]\frac{1}{2} * AB * BE[/latex]
= [latex]\frac{1}{2} * 3 * 2[/latex] = 3 sq. m.
Area of the rectangle = 10 * 2 = 20 sq. m.
i.e, Total area covered = 24.571 sq. m.
i.e, Prize money won by the person
= 24.571 * 100 = ₹ 2457
7. ABCD is a four-sided figure with AB parallel to CD and AD parallel to BC. ADE is right angle. If the perimeter of △ABE is 6 cm, then the area of the figure ABCD is
A. [latex]2 \sqrt{3} [/latex] sq. cm.
B. [latex]4 \sqrt{3} [/latex] sq. cm.
C. 3 sq. cm.
D. None of these
Answer - Option C
8. It is required to fix a pipe such that water flowing through it at a speed of 7 metres per minute fills a tank of capacity 440 cubic metres in 10 minutes. The inner radius of the pipe should be
A. [latex]\sqrt{2}[/latex] m
B. 2 m
C. [latex]\frac {1}{2}[/latex]
D. [latex]\frac {1}{\sqrt{2}}[/latex]
Answer - Option B
Explanation -
Explanation -
Volume of the pipe in one minute
= [latex] \pi * {r}^{2}(7) = \frac{440}{10} [/latex]
r = 2
9. Water flows out through a circular pipe whose internal diameter is 2 cm, at the rate of 6 metres per second into a cylindrical tank, the radius of whose base is 60 cm. By how much will be level of water rise in 30 minutes?
A. 2 m
B. 4 m
C. 3 m
D. 5 m
Answer - Option C
Explanation -
Volume of water in the tank = [latex]\pi {(60)}^{2}[/latex] × x
where, x = level of the water
Water released by pipe in 30 minutes
= [latex]\pi * {1}^{2}[/latex] × 600 × 30 × 60
Equating the two and solving, we get
[latex]\pi {(60)}^{2}[/latex] × x = [latex]\pi * {1}^{2}[/latex] × 600 × 30 × 60
x = 300 cm = 3 m
10. A plot of land in the form of a rectangle has a dimension 240 m × 180 m. A drainlet 10 m wide is dug all around it (one the outside) and the earth dug out is evenly spread over the plot, increasing its surface level by 25 cm. The depth of the drainlet is
A. 1.225 m
B. 1.229 m
C. 1.227 m
D. 1.223 m
Answer - Option C
Explanation -
Volume of the earth taken out = Volume of the earth on plot
= [{260 × 200} – {240 × 180}] × x
= 240 × 180 × [latex]\frac{1}{4}[/latex]
Solving, we get x = 1.227.
11. A square and an equilateral triangle have the same perimeter. If the diagonal of the square is [latex]12 \sqrt{2} [/latex] cm, then the area of the triangle is
A. [latex]24 \sqrt{3}{cm}^{2} [/latex]
B. [latex]24 \sqrt{2}{cm}^{2} [/latex]
C. [latex]64 \sqrt{3}{cm}^{2} [/latex]
D. [latex]32 \sqrt{3}{cm}^{2} [/latex]
Answer - Option C
Explanation -
Let x be the side of the square.
i.e, [latex]{x}^{2} + {x}^{2} = {(12\sqrt {2})}^{2}[/latex]
x = 12
Now, perimeter of the equilateral triangle
= perimeter of the square
= 4x = 48 cm
i.e, Side of the equilateral triangle = [latex]\frac{48}{3}[/latex] = 16 cm
Area of equilateral triangle
= [latex]\frac{\sqrt{3}}{4} * {16}^{2} = 64 \sqrt{3}{cm}^{2} [/latex]
12. Semi-circular lawns are attached to both the edges of a rectangular field measuring 42 m * 35m. The area of the total field is
A. 3818.5 [latex]{m}^{2}[/latex]
B. 8318 [latex]{m}^{2}[/latex]
C. 5813 [latex]{m}^{2}[/latex]
D. 1358 [latex]{m}^{2}[/latex]
Answer - Option A
Explanation -
Area B = Area D
Area C = Area E
Total area of the field
= Area of A + 2 * Area of B + 2 * Area of C
= 42 * 35 + 2 * [latex]\frac{}{} \pi {(21)}^{2} + 2 * \frac {1}{2}\pi {\frac({35}{2})}^{2}[/latex]
= 1470 + 1386 + 962.5
= 3818.5 [latex]{m}^{2}[/latex]
13. What is the area of the inner equilateral triangle if the side of the outermost square is ‘a’ ? (ABCD is a square)
A. [latex]\frac{3 \sqrt{3} {a}^{2}}{32}[/latex]
B. [latex] \frac{3 \sqrt{3} {a}^{2}}{64}[/latex]
C. [latex]\frac{5 \sqrt{3} {a}^{2}}{32}[/latex]
D. [latex]\frac{\sqrt{3 {a}^{2}} }{64}[/latex]
Answer - Option A
14. An edge of a cube measures 10 cm. If the largest possible cone is cut out of this cube, then volume of the cone is
A. 260 [latex]{cm}^{3}[/latex]
B. 260.9 [latex]{cm}^{3}[/latex]
C. 261.9 [latex]{cm}^{3}[/latex]
D. 262.7 [latex]{cm}^{3}[/latex]
Answer - Option C
Explanation -
Height of the cone = 10 cm
Radius of the base = [latex]\frac{10}{2}[/latex] cm = 5 cm
Hence volume of the largest possible cone cut out of this cube
= [latex]\frac{1}{3} * \frac{22}{7} * {(5)}^{2}* 10 = 261.8 {cm}^{3}[/latex]
15. In the figur e, ABCD is a square with side 10. BFD is an arc of a circle with centre C. BGD is an arc of a circle with centre A. What is the area of the shaded region ?
A. [latex]100 – 50 \pi[/latex]
B. [latex]100 – 25 \pi[/latex]
C. [latex]50 \pi - 100[/latex]
D. [latex]25 \pi - 100[/latex]
Answer - Option C
Explanation -
Area of the portion DFBC = [latex]\frac{1}{4} * \pi * {(10)}^{2} = 25 \pi[/latex]
i.e, Area of △BCD = [latex]\frac{1}{2} * 10 * 10 = 50 [/latex]
i.e, Area of the portion DFBOD = Area of the portion DFBC – Area of △BCD
= 25[latex]\pi[/latex] – 50
i.e, Area of the portion DFBGD
= 2 * Area of the portion DFBOD
= 2(25[latex]\pi[/latex] – 50) = 50[latex]\pi[/latex] – 100