Exercise :: Simplification - General Questions
- Simplification - Important Formulas
- Simplification - General Questions
1. | A man has Rs.480 in the denominations of one-rupee notes, five-rupee notes and ten-rupee notes. The number of notes of each denomination is equal. What is the total number of notes that he has ? |
|||||||
Answer: Option D Explanation: Let number of notes of each denomination be x. Then x + 5x + 10x = 480
Hence, total number of notes = 3x = 90. |
2. | There are two examinations rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B. The number of students in room A is: |
|||||||
Answer: Option C Explanation: Let the number of students in rooms A and B be x and y respectively. Then, x - 10 = y + 10 and x + 20 = 2(y - 20) Solving (i) and (ii) we get: x = 100 , y = 80.
|
3. | The price of 10 chairs is equal to that of 4 tables. The price of 15 chairs and 2 tables together is Rs. 4000. The total price of 12 chairs and 3 tables is: |
||||||||||||||||||||||
Answer: Option D Explanation: Let the cost of a chair and that of a table be Rs. x and Rs. y respectively.
Hence, the cost of 12 chairs and 3 tables = 12x + 3y = Rs. (2400 + 1500) = Rs. 3900. |
4. | If a - b = 3 and a2 + b2 = 29, find the value of ab. |
|||||||
Answer: Option A Explanation: 2ab = (a2 + b2) - (a - b)2 = 29 - 9 = 20 |
5. | The price of 2 sarees and 4 shirts is Rs. 1600. With the same money one can buy 1 saree and 6 shirts. If one wants to buy 12 shirts, how much shall he have to pay ? |
|||||||||
Answer: Option B Explanation: Let the price of a saree and a shirt be Rs. x and Rs. y respectively. Then, 2x + 4y = 1600 .... (i) and x + 6y = 1600 .... (ii) Divide equation (i) by 2, we get the below equation. => x + 2y = 800. --- (iii) Now subtract (iii) from (ii) x + 6y = 1600 (-) x + 2y = 800 ---------------- 4y = 800 ---------------- Therefore, y = 200. Now apply value of y in (iii) => x + 2 x 200 = 800 => x + 400 = 800 Therefore x = 400 Solving (i) and (ii) we get x = 400, y = 200.
|