Question
Three years ago, the ratio of ages of ‘Ravi’ and his
sister was 3:4. Three years from now, the ratio of ages of Ravi and his mother will be 2:5. In 9 years from now, the ratio of ages of Ravi’s sister and his mother will be 3:5. What is the current age of Ravi’s mother?Solution
ATQ,
3 years ago, let the age of Ravi = 3x years So, 3 years ago, age of Ravi’s sister = (4/3) × 3x = 4x years 3 years hence from now, age of Ravi = (3x + 6) years 3 years hence from now, age of Ravi’s mother = (3x + 6) × (5/2) = (15x + 30)/2 years 9 years hence from now, age of Ravi’s sister = (4x + 12) years 9 years hence from now, age of Ravi’s mother = (15x + 30)/2 + 6 = (15x + 42)/2 years ATQ; 4x + 12 = (15x + 42)/2 × (3/5) Or, 4x + 12 = {(45x + 126)/10} Or, 40x + 120 = 45x + 126 Or, 5x = 6 Or, x = 6 So, present age of Ravi’s mother = (15x + 30)/2 – 3 = (90 + 30)/2 – 3 = 60 – 3 = 57 years
- Which of the following numbers is not a perfect square?
A lending library has a fixed charge for the first 7 days and an additional charge for each day thereafter. Sahil paid Rs . 215 for a book kept for 15 ...
- A number exceeds 40 times its reciprocal by 7/8. Determine the number.
Find the greatest 4‑digit number which is exactly divisible by 12, 15 and 20.
In a two digit positive number, the digit in the unit’s place is equal to the square of the digit in ten’s place, and the difference between...
- Find the median of the following observations:
120, 125, 115, 130, 140, 135, 145 - Find the smallest number that is divisible by 14, 28, and 42.
Determine the highest possible value of (x + y) if the number '3x725y4' is divisible by 12.
Find the least number to be added to 1500 to make it a perfect square.
If y = 5, then what is the value of 10y