Answer:
Nolan took 100 seconds
Step-by-step explanation:
Topic: One unknown equation
let' s assing some variables
K = time took by kong to complete the mult test
N = time took by Nolan to complete the mult test
you ca express the time took by Kong in terms of Nolan's taken time like this
K = N - 15%N (15% less)
the problem says that K took 85 seconds so we have that
K = 85 s
let's replace this in the equation
85 = N - 15%N let's Factorize
85 = N(1-15%)
so we have that
N = 85 / (1-15%) or N = 85 / (1-0.15)
N = 85 / (0.85) = 100 s
So Nolan took 100 seconds to fullfil the mult test