1. The average age of 3 boys is 15 years. If the ratio of their ages is 3 : 5 : 7. What is the age of the youngest boy?
(1) 9
(2) 12
(3) 18
(4) 21
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Explanation :
(1) Sum of the ages of three boys = 3 * 15 = 45 years and ratio of their ages = 3 : 5 : 7
Sum of the ratios
= 3 + 5 + 7 = 15
Age of the youngest boy
= 3 / 15 * 45 = 9 years
2. A man engaged of a servant on the condition that he would pay him Rs. 900 and a uniform after one year service. He served only for months and received uniform and Rs. 650. Find the price of the Uniform?
(1) Rs. 80
(2) Rs. 90
(3) Rs. 100
(4) Rs. 1
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Explanation :
(3) 12 months salary
= Rs 900 + Uniform
9 months salary
= Rs. 650 + Uniform
= 3 months salary
= Rs. 250 [on subtraction]
9 months salary
= Rs. (3 * 250) = Rs. 750
Therefore Rs. 750
= Rs. 650 + uniform
The cost of uniform = Rs. 100
3. Find the complete reminder when a certain number divided successively by 3,5 and 7 leaves remainders 2, 3 and 4 respectively?
(1) 61
(2) 52
(3) 73
(4) 71
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Explanation :
(4) Here d1 = 3, d2 = 5, d3 = 7 (divisors)
r1 = 2, r2 = 3, r3 = 4 (remainders)
Therefore The complete remainder
= d1 d2 r3 + d1 r2 + r1
= 3 * 5 * 4 + 3 * 3 + 2 = 71
4. A number when dividetd by 221 gives a reminder 43. What remainder will be obtained by dividing the same number by 17?
(1) 9
(2) 8
(3) 7
(4) 5
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Explanation :
(1) Number = 221 * Q + 43
Where
Q is a positive integer
= 17 (13 Q + 2 ) + 9 Hence, the remainder is 9.
5. A man walks from p to Q at the rate of 5 kmph and returns from Q to P at 3 kmph. What is his average speed for the whole journey?
(1) 13 / 4 kmph
(2) 7 / 2 kmph
(3) 15 / 4 kmph
(4) 8 kmph
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Explanation :
(3) Here, PQ = QP.
Average speed
= 2 * 5 * 3 / 5 + 3 = 30 / 8 = 15 / 4 kmph.
6. The ratio between the Present ages of Ram and Mohan is 6 : 7 and the sum of their Present ages is 39 years. What is the age of RAM?
(1) 15 yrs
(2) 16 yrs
(3) 17 yrs
(4) 18 yrs
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Explanation :
(4) Let the present ages of RAM and mohan be 6 x and 7 x yrs respectively
Therefore 6 x + 7 x = 39
13 x = 39 = x = 3
Present age of RAM
= 6 x = 6 * 3 = 18 yrs.
7. In the following number series on term is wrong. FInd out the wrong term.
484, 441, 400, 360, 324
(1) 484
(2) 360
(3) 400
(4) 441
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Explanation :
(2) The series is based on the following pattern :
484 = (22)^2, 441 = (21)^2
400 = (20)^2, 361 = (19)^2
324 = (18)^2
Hence the wrong one is 360
8. Which fraction is the smallest ?
17 / 26, 9 / 13. 33 / 52, 37 / 52
(1) 33 / 52
(2) 17 / 26
(3) 9 / 13
(4) 37 / 52
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Explanation :
(1) First of all we make the denominator of each fraction equal.
9 / 13 = 9 * 4 / 13 * 4 = 36 / 52
17 / 26 = 17 * 2 / 26 * 2 = 34 / 52
others are, 33 / 52 , 37 / 52
obviously, 33 / 52 is smaller
9. By selling 25 metres of cloth. I gained the selling price of 5 metres,. The gain percent is equal to :
(1) 25%
(2) 20%
(3) 27%
(4) 22%
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Explanation :
S.P. = C.P. + Gain
Therfore S.P. of 25 metres = C.P. of 25 metrres + S.P. of 5 metres or S.P. of (25 – 5) metres
= C.P. OF 25 metres.
On every 20 metres sold, there is a gain of 5 metres. Let the rate be Re 1/metre.
Therefore Gain % = 5 / 20 * 100 = 25%
10. The compunded ratio of 5 : 14 and 7 : 15 is :
(1) 6 : 1
(2) 1 : 6
(3) 3 : 2
(4) 2 : 3
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Explanation :
(2) The required ratio
= 5 / 14 * 7 / 15 = 1 / 6 = 1 : 6