Xavier Aptitude Test 2023 Paper

Let ' $a$ ' and ' $b$ ' be the speeds of Rahim and the speed boat in still water, respectivelyLet 'c' be the speed of the stream.Speed boat starts after 1 minute of Rahim's departure and crosses him after 4 minutes.It implies that the speed boat covered the same distance in 4 minutes that Rahim took 5 minutes.Hence, the ratio of upstream speeds of Rahim and Speed boat $=\;\frac{a-c}{b-c}=\;\frac{4}{5}$Using Statement 1, we get $b=30\,\text{kmph}$. But, it's not sufficient to get the value of 'a'.Using Statement 2 , we get $a-c=\;\frac{30}{3}=10\,\text{kmph}$. But it's also not sufficient to get the value of 'a'. using both statements, we get $\;\;\frac{a-c}{b-c}=\;\frac{4}{5}$$\;\;\frac{10}{30-c}=\;\frac{4}{5}$$\;50=120-4c$$\;c=17.5$$\;a=17.5+10=27.5\,\text{kmph}$