The number of ways in which 20 letters $x_{1}, x_{2}, . . . . . . . x_{10}, y_{1}, y_{2},, . . . . . y_{10}$ be arranged in a line so that suffixes of the letters x and also those of y are respectively in ascending order of magnitude is

126

No worries! We‘ve got your back. Try BYJU‘S free classes today!

2^{20}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

^{20} C_{10}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is C $^{20} C_{10}$
From $20$ places $10$ places can be selected in $^{20} C_{10}$ ways.
In these cases x's can be arranged in ascending order in only one way. In the remaining places y's can be arranged in ascending order in only one way.
Hence required no. of arrangements $=^{20} C_{10}$

Suggest Corrections

Similar questions

20

a_{1}, a_{2}, a_{3}, \dots, a_{10}, b_{1}, b_{2}, b_{3}, \dots, b_{10}

a

b

x

y

x - y =

" A R R A N G E "

R^{'} s

Join BYJU'S Learning Program