Problems like this are straightforward to solve, once you've translated the information supplied into equations.
So: Let Deac and Irina be respectively A and B years old.
From the first bit: A + 7 = 2(B+7) Tidy this up: A + 7 = 2B + 14, and A - 2B = 7
From the second bit: A - 4 = 3(B-4), A - 4 = 3B - 12, and 3B - A = 8
We have to solve the two equations in bold simultaneously, which in this case is nice and easy. Simply adding the two equations together eliminates A: [A - 2B] + (3B - A) = [7] + (8) so B = 15 Having found B, we look back to a previous equation... A - 2B = 7, A - 30 = 7, A = 37 ...to find A.
So, Deac is 37 and Irina is 15.
Sister = 5 David = 13
Ralph is 3 times as old as Sara. In 6 years, Ralph will be only twice as old as Sara will be then. Find Ralph's age now.Which of the following equations could be used to solve the problem?
13 and 8
$10,000 times (1.1)3 = $13,310
11/53
Krishna is 12 and three times as old as his brother, who must be 4. In 4 years time when Krishna is 16 he will be twice as old as his brother, who will then be 8.
15.
28
Joe is 10 years older than James. In 8 years, twice Joe's age will equal three times James's age. How old is each now?
Mary is dead
Mary is 4 years old. [A+]
John will be 16.
son is 10, father is 33
12,4...16,8
Amy will be 16 when she is twice as old as Emily at 8.
Mike is 12. Mary is 4. In 4 years, Mike will be 16 and Mary will be 8. So Mike will be twice as old as she is in four years.
32