Question

What is the sum of all numbers between 100 and 1000 which are divisible by 14 ?

Answer 1

the number closest to 100 which is greater than 100 and divisible by14 is 112, which is the first term of the series which has to be summed.The number closest to 1000 which is less than 1000 and divisible by 14 is 994,which is the last term of the series.112 + 126 + .... + 994 = 14(8+9+ ... + 71) = 35392.

Answer 2

Answer: 35392

Step-by-step explanation:

The numbers that lie between 100 and 1000 which are divisible by 14 are 112, 126,140 ...,994

a = 112; l = 994, d = 14

n= (l−a)/d+1

= (994-112)/14+1

= 64

Sn=n/2(l+a)

= 64/2(994+112)

= 32*1106

= 35392