CAT 2015 Quantitative Ability

Question : 5 of 34

Marks: +1, -0

There are 40 students in a class. A student is allowed to shake hand only once with a student who is taller than him or equal in height to him. He can’t shake hand with anyone who is shorter than him. Average height of the class is 5 feet. What is the difference between the maximum and minimum number of handshakes that can take place in the class?

$[{C↖{40}_2} /2 - 20]$
361
${C↖{40}_2} -40$
${C↖{40}_2}$

Validate

Solution:

If all are of equal height, number of handshakes

= ^40 C_2

.
If all are of different heights, number of handshakes= 0.

\text"Difference" = C↖{40}_2 - 0 = C↖{40}_2

Go to Question:

Prev Question

Next Question