Surface area of a Rectangular parallelepiped of volume 64 cm3 and dimensions 1,b. h (all different integers) | Surface area of a cube having volume 64 cm3 |
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Solution
Col. A-
Surface area = 2(ℓb+ ℓh + bh)
For all distinct integral values of t , b, h such as (1, 2, 32) (1, 4, 16) (2,4,8) the surface area is more than 96 cm3.
Col. B-
Volume is 643. ∴ Side = 4 cm.
Surface area = 6 × (4)2 = 96 cm2
weight of lightest person | 40 kg. |
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Solution
Total weight of 3 people = 210 kgs.
∴ Total weight of remaining 2 people = (210 - 82) = 128 kgs. The second heaviest person will be maximum 81 kg.
∴ The lightest one has to weight at least 47 kgs. to make the total 210 kgs
Percentage increase required in the reduced price so as to reach a price that is 1.5 times the original price . | 125% |
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Solution
(3⁄5)th of original price = $7,200
∴ Original price = 12,000
1.5 times original = 18,000
∴ Increase required from $7,200 is $10,800.
∴ % increase =\(\frac{10800\times 100}{7200}\)= 150%
Length of other diagonal | 16√2 |
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Solution
Perimeter = 52 cm. ∴ Side = 3 cm.
Diagonals of a rhombus are ⊥ bisectors of each other.
∴ Other diagonal is 24.
Col. B 16√2 = 16 × 1.414 which will be less than 24.
Area of an equilateral triangle with side 4 cm. | Area of an square diagonal of length 4 cm. |
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Solution
Col. A = \(\frac{\sqrt{3}}{4}\times (4)^{2}\) × (4)2 = 4√3
Col. B = \(\frac{(4)^{2}}{2}\)= 8
Area of rectangle ADEH | 4 |
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Solution
Col. A-
Each angle of octagon is 135°
∴ ΔABJ is a right angle isosceles Δ. Since hypotenuse is √2 sides BJ and AJ are 1 each.
∴ Area of rectangle ADEH = 3
x co-orclinate of B | y co-ordinate of B |
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Solution
Area = 1⁄2 × (13) × (y co-ordinate) = 39
∴ y co-ordinate = 6
However x co-ordinate can take any position without altering the area.
C | 240 |
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Solution
Col. AC-
\(\frac{3C}{4}+\left ( \frac{3}{4}\times \frac{4}{5} \right )C=170\)
∴ 20C - 15C + 12C = 3400
∴ 17C = 3400 ∴. C = 200
Total no. of people left at Part! after 8 males leave | 24 |
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Solution
Let 'm' males and 'f females be originally present.
Condition 1 m = 3(f - 3) ∴ m = 3f - 9
Condition 2 m - 8 = 2(f - 3) ∴ m = 2f + 2
3f - 9 = 2f + 2 ∴ f = 11 ∴ m = 24
∴ First 3 females and then 8 males leave the party.
∴ No. of people left in the party (24 + 11) - (3 + 8) = 24
the digit in tens place.
Digital in hundred’s place | 5 |
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Solution
The 3 digit number must necessarily end in 0, because if it ends in 5, then according to given condition the number at ten's digit would be 2 digit number which is not possible. The maximum value for digit in ten's place will be 8, for which the maximum digit in hundred's place is 4. e.g., 120,240,360,480.