In a row of girls, if Madhu, who is. tenth from the left, and Veena. who is ninth from the right interchange their places, Madhu becomes fifteenth from the left. How many girls are there in the row ?

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?

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 $\mathrm{L}2$?

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?