The total cost of renting a boat was originally to be shared by 5 people. If number of people is increased by 1, the cost per person will be $10 less.
Total cost of renting the boat | $ 250 |
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Solution
5x = 6(x -10) .∴ x = 60
∴ Cost = 5x = $300
Angle between hour hand and minute hand at 1.10 p.m | 30° |
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Solution
Since the hour hand also moves downwards 10 minutes, actual distance between hour hand and minute hand is less than 5 minutes i.e. than 30°.
Distance at 1.05 p.m. between two hands is
(theoretical difference in time × 6° ) - (time × 1⁄2°)
(5 × 6°) - (10 × 1⁄2°) = 30° - 5° = 25°
In the diagram below ACD & BCE are straight lines.
∠ A – ∠ D | ∠ E – ∠ B |
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Solution
Col. 1 ∠A + ∠B + ∠C = 180°
Col. 2 ∠E + ∠C + ∠D = 180°
∴ ∠A + ∠B = ∠D + ∠E
∴ ∠A - ∠D = ∠E - ∠B
Letters are put into N envelops so that each envelop contains at least 1 letter, but no two envelopes contain same number of letters.
maximum possible envelopes that certain a total of 39 letters | 9 |
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Solution
Let 8 envelopes contain 1,2,3,4,5,6,7, letters respectively.
We are left with three letters which can be put any of the 6th, 7th or 8th
∴ Total envelopes = 8
x lies between 4 and 16 (both inclusive) and y between 24 and 48 (both inclusive).
Maximum possible value for x⁄y | \(\frac{16}{48}\) |
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Solution
Col. A \(\frac{16}{24}\) = 2⁄3
Col. B = 1⁄3
Ratio of surface area of cube of edge 2 cm to that of edge 3 cm. | Ratio of volume of cylinder with radius 4 cm to that of radius 6 cm. and having equal height |
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Solution
Col. A \(\frac{6 \times (2)^{2}}{6 \times (3)2^{2}}=\frac{4}{9}\)
Col. B \(\frac{\pi (4)^{2}h}{\pi (6)^{2}h}=\frac{4}{9}\)
r | 2.5t |
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Solution
R = 3S = 6T ∴ πr2 = 6m2
∴ r = √6 t.........Col. A
Col. B - 2.5t = \(\sqrt{6.25}\) t
Length BD | 20 |
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Solution
ABCD need not be a square ∴ BD need not be the diameter.
∴ Length of BD cannot be exactly determined.
No. of arrangements that can be made of the letters of the word EDUCATION with the vowels never being separated. | 1.44 × 105 |
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Solution
The word has 5 vowels and 4 consonants.
∴ No. of arrangements = 5! x 5! (5!) for 4 consonants and the block of vowels and again 51 for 5 vowels)
= (120)2 = 14400 = 1.44 × 104
the present age of the oldest person | 8 years |
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Solution
If the average after 8 years is twice their average age now, average age today must be 8. So that average after 8 years will be 16.
∴ Present ages are 6,8,10