1 .
Each interior angle of a regular polygon is 120° greater than each exterior angle. How many sides are there in the polygon?
Answer & Explanation
Answer : Option C |
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Explanation : |
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Let an exterior angle $A^o$
Then each interior angle will be 120 + $A^o$
We know that in any regular polygon, the sum of an exterior and interior angle is always = $180^o$
A + 120 + A = 180 $\Rightarrow$ A = $30^o$
No. of sides of a polygon = $360 \over 30$ = 12 |
2 .
In what ratio should a 20% methyl alcohol solution be mixed with a 50% methyl alcohol solution, so that the resultant solution has 40% methyl alcohol in it?
Answer & Explanation
Answer : Option A |
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Explanation : |
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3 .
A, B and C can do a piece of work in 15 days. All three worked for 2 days and then A left. B and C worked for 10 more days and B left. C worked for another 40 days and completed the work. In how many days can A alone complete the work, if C can complete it in 75 days?
Answer & Explanation
Answer : Option A |
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Explanation : |
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Assume the total work to be 600 units.
(LCM of all the numbers)
Then C's 1 day work = 8 units.
$\Rightarrow$(A + B + C)'s 1 day work = 40 units.
A, B, C work together in the first 2 days
$\Rightarrow$Work done in the first 2 days
= 40 $\times$ 2 = 80 units
C alone works during the last 40 days
$\Rightarrow$Work done in the last 40 days
= 40 $\times$ 8 = 320 units
Remaining work = 600 - (320 + 80)
= 200 units
This work is done by B and C in 10 days.
$\Rightarrow$(B + C)'s 1 day work = 20 units
$\Rightarrow$A's 1 day work = (A + B + C)'s 1 day work -
(B + C)'s 1 day work = 40 units - 20 units =
20 units
$\Rightarrow$A can do the work of 600 units in $600\over 20$
= 30 days |
4 .
A tower standing on a horizontal plain subtends a certain angle at a point 160 m apart from the foot of the tower. On moving 100 m towards the tower, it is found that the subtended angle is now twice as before. What will be twice the length of the height of the tower?
Answer & Explanation
Answer : Option B |
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Explanation : |
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5 .
If $2x^2 + 5 x + 1 \over 5x$ = 3, then $2x \over 2x^2 + 1$ = ?
Answer & Explanation
Answer : Option C |
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Explanation : |
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6 .
The average age of a college is 21.8 years. The average age of students of college is 24.2 years and average age of lecturers of college is 20.6 years. Find the ratio of the number of students to that of lecturers?
Answer & Explanation
Answer : Option D |
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Explanation : |
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7 .
A man and a woman 81 miles apart from each other, start travelling towards each other at the same time. If the man covers 5 m/hr to the women's 4 m/hr, how far would the woman have travelled when they meet?
Answer & Explanation
Answer : Option B |
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Explanation : |
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Time taken to meet = $Distance\,\,\, between \,\,\,them\over Relative \,\,\,speed$
= $81 \over (4 + 5)$ = 9 hrs
Distance traveled by women = 9 $\times$ 4
= 36 miles |
8 .
Find the total surface area of the pyramid with base length and height be 10 cm and 12 cm respectively
Answer & Explanation
Answer : Option B |
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Explanation : |
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9 .
If x + $2\over x$ = 1. then $x^2 + x + 2 \over x^2 (1 - x)$ = ?
Answer & Explanation
Answer : Option C |
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Explanation : |
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10 .
A wheel of a car of radius 21 cm is rotating at 600 RPM. What is the speed of the car in km/hr?
Answer & Explanation
Answer : Option B |
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Explanation : |
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The radius of the wheel measures 21 cm.
In one rotation this wheel will cover
= 2 $\times$ $\pi$ $\times$ 21 = 132 cm.
In an hour, the wheel will cover a distance of (132 $\times$ 600) $\times$ 60 = 4752000 cm.
The speed of the car = 4752000 cm/hr
= 47.52 km/hr |
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