Question

how many 3 digit numbers are devisible by 7​

Answer 1

Answer:

Three Numbers which are divisible by 7 are

105,112,119,.....994

which forms an A.P

first term of this A.P a

1

=105

second term of this A.P is a

2

=112

common difference of this A.P is

d=a

2

−a1=112−105=7

nth term of this A.P is given by

a

n

=a

1

+(n−1)d

⟹a

n

=105+(n−1)7

⟹a

n

=105+7n−7

⟹a

n

=98+7n...….eq(1)

for finding number of terms(n) in this A.P put last term a

n

=994 in eq(1)

⟹994=98+7n

⟹7n=994−98

⟹7n=896

⟹n=

7

896

⟹n=128

hence, their are 128 three digit numbers which are divisible by 7

Answer 2

$☆here \: is \: ur \: answer☆\:$

There are 128 3-digits number which are divisible by 7

$hope \: it \: helps \: you.....$