AlgebraMediumAges of three siblings from a sum and two differences
Algebra practice question
The ages of three siblings add up to 34. The middle sibling is 2 years older than the youngest and 3 years younger than the eldest. How old is the youngest?
Answer: 9
Let the youngest be y: y + (y + 2) + (y + 5) = 34 → 3y + 7 = 34 → y = 9.
Common wrong answers
- If you answered 11
- 11 is the middle sibling.
- If you answered 12
- 12 comes from 3y − 2 = 34, subtracting the differences instead of adding.
- If you answered 14
- 14 is the eldest.
More Algebra questions
- Medium
A system: 2x + y = 11 and x − y = 1. What is the value of x + y? - Medium
Which of the following describes all solutions to 4x − 9 ≤ 2x + 5? - Medium
A phone's battery percentage is modeled by P = 100 − 8t, where t is the number of hours since it was unplugged… - Medium
If y = 2x − 1 and 3x + y = 14, what is the value of x? - Medium
If |2x − 3| = 7, what is the sum of all possible values of x? - Medium
Line k has equation y = (2/3)x + 1. Which equation represents a line perpendicular to line k?
Not affiliated with the College Board. SAT is a trademark of the College Board.