Kong took 85 seconds to complete his multiplication timed test. Consider the proportion:
Nolan took x seconds - 100%
Kong took 85 seconds - 100%-15%=85%
That is mathematically
[tex]\dfrac{x}{85}=\dfrac{100}{85},\\ \\x=\dfrac{100\cdot 85}{85}=100\ seconds.[/tex]
Answer: Nolan took 100 seconds to complete the test.
