Raja walks slower than Raghu and Raghu walk faster than Guru and Krishna walks faster than Guru, than who walks fastest among them ?

Rohit is ranked ${18}^{\mathrm{th}}$, from the top in his class. When counted from the bottom, he is ranked ${36}^{\mathrm{th}}.$ What is the total number of students in the class$?$

Ravi is $7$ ranks ahead of Sumit in a class of $39$. If Sumit's rank is seventeenth from the last, what is Ravi's rank from the start?

A pole is taller than a Giraffe which is taller than a Tree. A signal is shorter than a pole, but taller than a building which is taller than a Giraffe. Who is the shortest ? 

1. Signal
2. Giraffe
3. Tree
4. Building

Five balls $\mathrm{L}1, \mathrm{L}2, \mathrm{L}3, \mathrm{L}4 \mathrm{and} \mathrm{L}5$, are kept one above the other (not necessarily in the same order). $\mathrm{L}1$, is just above $\mathrm{L}5$, and just below $\mathrm{L}4$. $\mathrm{L}2$, is just above $\mathrm{L}3$, and just below $\mathrm{L}5$ . How many balls are above $\mathrm{L}2$?

There are $50$ buildings in a row. The green building is $14\mathrm{th}$from the right end. What is its position from the left end?

Among five friends - O, P, Q, R, and S, each scored different marks in an examination. P scored more than R and Q, but less than O. O did not score the highest marks and did not score the lowest marks. Who amongst the following scored the third highest?