Question

what is the sum of all numbers between 100to1000which are divisible by 14​

Answer 1

35392Explanation : 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.

Hope it helps you....

Answer 2

Answer:

bet ween 100 and 1000

a=112

lats term is 994

d=14

now ,

an=a+(n-1)d

994=112+(n-1)14

=994-112=(n-1)14

=882/14=n-1

=63+1=n

=64=n

sum =n/2{2a+(n-1)d}

sum=64/2{2×112+(64-1)14}

sum=32{224+(63×14)}

sum=32{224+882}

sum=32×1106

sum=35392