Vector Problem: Clarity on Part (f) & Why 2.15 Only

[chwala]

Homework Statement

kindly see attached problem

Relevant Equations

vectors

i need clarity on part (f) only...we have two values for $t$ i.e $t=2.79$ and $t=2.15$, ...the mark scheme says solution is:

why $2.15$ only, i have tried substituting the two values back into the problem and they both satisfy part $e$

 

[chwala]

I need help on part $f$ only.

 

[FactChecker]

Which of the two time values that you got is first?

 

[chwala]

Which of the two time values that you got is first?

ok i see quite tricky...thanks mate.