WBCS Mains 2021 (Held On May 2022) Official Paper-VI

If the average marks of three batches of $55$, $60$ and $45$ students respectively is $50$, $55$, $60$, then the average marks of all the students is:

Find the largest possible $4$ -digit number divisible by $45$, $18$ and $35$.

If a car is sold for $\text{Rs. }50,000$ the profit is $17\%$, what would be the profit percentage if it were sold for $\text{Rs. }47,000$?

If $\tan \theta +\sec \theta =4$, then what is the value of $\cos \theta$?

In a certain code 'a friend of mine' is written as '4916', 'mine lot of metal' is written as '3109' and 'a piece of metal' is coded as '7163'. How can '673' be written in the same coding system?