If (A(t)=70+9t) and (B(t)=118+5t), at what (t) will (A(t)) be (8) more than (B(t))?
Answer and explanation
Correct answer: \(t=14\)
The condition is \(A(t)=B(t)+8\). Thus, \(70+9t=118+5t+8\), which gives \(4t=56\) and hence \(t=14\). Therefore, \(t=14\) is correct. At the closest distractor, \(t=13\), the difference between the functions is only \(4\), not \(8\). Exam tip: Translate “8 more than” as adding \(+8\) to the second expression before forming the equation.
Frequently asked questions
What is the correct answer to this question?
\(t=14\)
Why is this the correct answer?
The condition is \(A(t)=B(t)+8\). Thus, \(70+9t=118+5t+8\), which gives \(4t=56\) and hence \(t=14\). Therefore, \(t=14\) is correct. At the closest distractor, \(t=13\), the difference between the functions is only \(4\), not \(8\). Exam tip: Translate “8 more than” as adding \(+8\) to the second expression before forming the equation.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear growth and decay.
