| **Answers & Solutions ** | | 1 . | Answer : Option C | Explanation : | Let the number of 50 p, 25 p and 10 p coins be 5x, 9x and 4x respectively. Then, $5x\over2$+$9x\over4$+$4x\over10$ = 206 $50x+45x+8x=4120$ $103x=4120$ $x=40$ Number of 50 p coins = (5 × 40) = 200; number of 25 p coins = (9 × 40) = 360; number of 10 p coins = (4 × 40) = 160 | | | 2 . | Answer : Option D | Explanation : | Let the length of sheet of paper be x cm. Then the ratio of length to width = x : 18 Thus, x : 18 = 5 : 3 x × 3 = 18 × 5 x = 30 Hence the length of paper = 30 cm | | | 3 . | Answer : Option A | Explanation : | 5 : 7 = x : 56 (suppose number of men = x) x = 40 (by the first property) Therefore, number of men in the office = 40 | | | 4 . | Answer : Option B | Explanation : | $(a+b)\over(a-b)$=$15\over1$ $a\over b$ = $8\over7$ (by compnendo and dividend) Therefore, $a^ 2$ - $b^ 2$ = 64-49 = 15 | | | 5 . | Answer : Option B | Explanation : | 2x + 40 = 4y … (i) 3x + 40 = 5y …. (ii) 4x + 40 = 6y ….. (iii) Therefore 2x = 40 x = 20 Hence, total number of students = 2x + 3x + 4x = 9x = 9 × 20 = 180 | | | 6 . | Answer : Option B | Explanation : | Milk $\,\,\,\,\,$ 20% $\,\,\,\,\,$ 25% Water $\,\,\,$ 80% $\,\,\,\,$ 75% Therefore, required ratio =$80\over75$=$16\over15$ or 16:15 | | | 7 . | Answer : Option C | Explanation : | Ratio of speed of camel and elephant = $5\over3$:$7\over5$=$5\over3$$\times$15:$7\over5$$\times$15=25:21 | | | 8 . | Answer : Option C | Explanation : | Let the age of son is x years, then the age of Sachin will be 4x years. So, (4x - 5) = 9 (x - 5) | x = 8 So, age of Sachin is 32 years. | | | 9 . | Answer : Option D | Explanation : | Ratio of shares of Bhanu and Shafeeq = 36000 : 63000 = 4 : 7 So, Share of Bhanu = 5500 × $4\over11$ = Rs.2000 And share of Shafeeq = 5500 x $7\over11$ = Rs.3500 | | | 10 . | Answer : Option C | Explanation : | [$A\over B$ = $3\over 4$, $B\over C$=$8\over 9$] $A\over C$= [$A\over B$$\times$$B\over C$] = [$3\over 4$$\times$$8\over 9$] = $2\over 3$ A:C = 2:3 | | | | |

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