Question
Four years ago, the ratio of ages of 'X' and 'Y' was 2:3
respectively. Six years from now, the ratio of their ages will become 4:5 respectively. If 'Z' is 7 years older than 'Y', then what is the average current age (in years) of 'X' and 'Z'?Solution
ATQ,
Let the age of 'X' and 'Y' four years ago be '2n' and '3n' years respectively.
So, (2n + 4 + 6) : (3n + 4 + 6) = 4:5
Or, 5 × (2n + 10) = 4 × (3n + 10)
Or, 10n + 50 = 12n + 40
Or, 2n = 10
Or, 'n' = 5
Present age of 'X' = 2 × 5 + 4 = 14 years
Present age of 'Y' = 3 × 5 + 4 = 19 years
Present age of 'Z' = 19 + 7 = 26 years
Required average = (14 + 26) ÷ 2 = 20 years
When a number is divided by 17 remainder is 11. Find the remainder when five times of the same number is divided by 17.
The cost of 3 notebooks and 2 erasers is Rs.47, and the cost of 5 notebooks and 4 erasers is Rs.83. What is the total price (in Rs) of 2 notebooks and 3...
What is the greatest four-digit number that leaves remainders 1, 2 and 3 respectively when divided by 2, 3 and 4?
- Determine the value of 'n' if '87n9812' is always divisible by 9.
How many unique five-digit numbers can be created using the digits 0, 1, 5, 6, 7, and 8, without repeating any digit?
If z = 3 – 4i, find |z²|.
When N is divided by 5 the remainder is 2. What is the remainder, when n³ is divided by 5?
Find the unit digit of the expression: 1! + 4! + 6! + 9! + 25!.
A number is increased by 20% then reduced by 20%. If final value is 144, find original number.
If 'N' is the greatest four digit number which when divided by 27, 6, 8 and 9 Leaves in each case the same remainder of 5, then the sum of the digits of...