Question

how many multiples of 7 between 100 and 1000

Answer 1

So AP is 105,112,119...........994
then, d=7, a=105, an=994, n=?
So, we know that
an=a+(n-1)d
994=105+(n-1)7
994-105=7n-7
889+7=7n
896=7n
128=n or
n= 128

I hope it will help you
please mark as brainliest answer

Answer 2

To find:

"Multiples of 7” between 100 and 1000

Answer:

The first multiple of 7 starting from 100 is 105

The last multiple of 7 starting from 100 to 1000 is 994

Consider the series is an AP with a = 105, d (common difference) = 7 and the last term l = 994

We can find the "number of terms" by the following formula

$N = \frac {l-a} {d} +1$

$N = \frac {994-105}{7} +1$

$N= \frac {889}{7} +1$

$N= 127 +1$

$N = 128$

128 multiples are there from 100 to 1000

i.e. 105, 112, 119,  ….. 973, 980, 987 and 994