A father says to his daughter Kavya: 'Seven years ago, I was seven times as old as you were. Three years from now, I will be three times as old as you will be.' Let present ages be f and k: f - 7 = 7(k - 7) and f + 3 = 3(k + 3). Use substitution to find Kavya's present age (in years).

Question

Accepted Answer

12. From f + 3 = 3(k + 3), f = 3k + 6. Substitute into f - 7 = 7(k - 7): (3k + 6) - 7 = 7k - 49, 3k - 1 = 7k - 49, 48 = 4k, k = 12. Kavya is 12 years old.

A father says to his daughter Kavya: 'Seven years ago, I was seven times as old as you were.
Three years from now, I will be three times as old as you will be.'
Let present ages be f and k: f - 7 = 7(k - 7) and f + 3 = 3(k + 3).
Use substitution to find Kavya's present age (in years).

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Substitution Method practice

A father says to his daughter Kavya: 'Seven years ago, I was seven times as old as you were.Three years from now, I will be three times as old as you will be.'Let present ages be f and k: f - 7 = 7(k - 7) and f + 3 = 3(k + 3).Use substitution to find Kavya's present age (in years).

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Substitution Method practice

A father says to his daughter Kavya: 'Seven years ago, I was seven times as old as you were.
Three years from now, I will be three times as old as you will be.'
Let present ages be f and k: f - 7 = 7(k - 7) and f + 3 = 3(k + 3).
Use substitution to find Kavya's present age (in years).