Question

How many numbers
between
1and 400 are
are exactly
divisible by 7?​

Answer 1

Answer:

How many numbers

between

1and 400 are

are exactly

divisible by 7?

Answer 2

• We have to find the numbers that are divisible by 7 between 1 to 100.

Number of terms (n) = ?

Numbers are : 7, 14, 21, 28, ........, 399

» A.P. = 7, 14, 21, 28, ......, 399

Here

First term (a) = 7

Common difference (d) = a2 - a1 = 14 - 7 = 7

Last term (l) = 399

______________________________

l = a + (n - 1)d

Put the given values in above equation

=> 399 = 7 + (n - 1)(7)

=> 399 - 7 = (n - 1)7

=> 392 = (n - 1)7

=> $\dfrac{392}{7}$ = n - 1

=> 56 = n - 1

=> n = 56 + 1

=> n = 57

______________________________

57 numbers are exactly divisible by 7 between 1 to 100.

__________ [ANSWER]