The number of numbers between 105 and 1000 which are divisible by 7 is...
To find the number of numbers between 105 and 1000 that are divisible by 7, we need to determine the range of numbers that satisfy this condition.
Step 1: Find the smallest number greater than or equal to 105 that is divisible by 7.
The smallest number greater than or equal to 105 that is divisible by 7 is 105 itself.
Step 2: Find the largest number less than or equal to 1000 that is divisible by 7.
To find the largest number less than or equal to 1000 that is divisible by 7, we divide 1000 by 7 and take the integer part of the quotient. This is because the largest number divisible by 7 would be a multiple of 7.
1000 ÷ 7 = 142.857
Since we need to find the largest number less than or equal to 1000, we take the integer part of 142.857, which is 142.
Therefore, the largest number less than or equal to 1000 that is divisible by 7 is 7 * 142 = 994.
Step 3: Calculate the number of numbers divisible by 7 between 105 and 1000.
To calculate the number of numbers divisible by 7 between 105 and 1000, we subtract the smallest number divisible by 7 from the largest number divisible by 7 and divide the result by 7.
(994 - 105) ÷ 7 = 889 ÷ 7 = 127
Therefore, there are 127 numbers between 105 and 1000 that are divisible by 7.
Hence, the correct answer is option C) 128.
The number of numbers between 105 and 1000 which are divisible by 7 is...
Clearly, the numbers between 105 and 1000 which are divisible by 7 are 112,119,126,...,994.
This is an AP with first term a=112, common difference d=7 and last term l = 994.
Let there be n terms in this AP. Then,
an = 994
⇒ a + (n − 1)d
994 = 112 + (n − 1) × 7
994 = 105 + 7n
∴ 7n = 889
∴ n = 127