Question

how many 4 digit numbers are divisible by 3 in arithmetic progression​

Answer 1

Answer:

Least 4 digit number=1000.

Highest 4 digit number=9999.

1002,1005,…..,9999.

The above series is in A.P. Here we have to calculate the n value.

a=1002,d=3 and Tn=9999.

Tn=a+(n-1)d

==>9999–1002=(n-1)*3

==>n-1=2999

Therefore, 3000 four digit numbers are divisible by 3.

Answer 2

Answer:

4 digits numbers divisible by 4 are

1002, 1005, 1008,..., 9999

Here a = 1002, d = 3

tn= a+(n-1)d

9999 = 1002 + (n-1)X3

(n-1)X3 = 9999 - 1002

(n-1)X3 = 8997

n - 1  = 8997/3

n - 1 = 2999

n = 2999+1

n = 3000

So there are 3000 numbers of 4 digit numbers that are divisible by 3 and in arithmetic progression

Step-by-step explanation: