Book Online Demo

Check Your IQ

Try Test

Courses

Offline Centres

Which three-digit natural number is divided by 7?

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

135

128

125

130

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

The three digit natural number that are completely divisible by 7 are:

105, 112, 119, … … … …, 994

As first term:

a 1

=105, second term:

a 2 = 112

∴ d = a 2 − a 1 ⇒ d = 112 − 105 ⇒ d = 7

The above numbers are in the form of AP as the consecutive numbers have a common difference of 7.
Let that this AP contain n number of terms:

∴ a n = 994

Formula used for

n t h

term of A.P.:

a n = a + n − 1 d

Applying formula

⇒ 105 + (n − 1) × 7 = 994 ⇒ 7 n + 98 = 994 ⇒ 7 n = 994 − 98 ⇒ 7 n = 896

⇒ n = 8967 ⇒ n = 128

Therefore, there are 128 three digit numbers that are divisible by 7.
Hence, option (3) is correct.

Watch 3-min video & get full concept clarity

JEE

NEET

Foundation JEE

Foundation NEET

CBSE