Question

how many three digit positive integers are there such that each is a multiple of 11 that contains distinct digits​

Answer 1

Answer:

81

Step-by-step explanation:

3-digit numbers divisible by 11 are:

110 ,121 ,132 ,143 ,154 .... 990

here,

a = 110

d = a2 - a1 = 121 - 110 = 11

990 is the last term of the A.P of 3-digit numbers which is divisible by 11.

an =  a+(n-1)d

990 = 110 + (n-1) 11

990-110 = 11n - 11

880 + 11 = 11n

n = 891 / 11

n = 81

therefore ,there are 81 ,3-digit positive integers which are multiple of 11.