2026 · Q35
Two numbers P and Q are such that P:Q = x:y. If 1 is added to both the numbers, the ratio becomes 7:10. If 3 is added to both the numbers, the ratio becomes 3:4. What is (x + y):(x - y) equal to?
Elementary MathematicsRatio and Proportion
- A-5
- B-3
- C3
- DCannot be determined due to insufficient data
Explanation
From (P+1)/(Q+1)=7/10 we get 10P−7Q=−3, and from (P+3)/(Q+3)=3/4 we get 4P−3Q=−3. Solving yields P=6, Q=9, so P:Q=2:3 and (x+y):(x−y)=(2+3):(2−3)=−5, option A. A frequent error is assuming P:Q itself equals 7:10 or 3:4 instead of solving the two ratio equations.