As per given a=72, d=-2, l=40 Therefore, l=a+(n-1)d 40=72+(n-1)(-2) =72-2n +2 2
As per given a=72, d=-2, l=40 Therefore, l=a+(n-1)d 40=72+(n-1)(-2) =72-2n +2 2 As per given a=72, d=-2, l=40 Therefore, l=a+(n-1)d 40=72+(n-1)(-2) =72-2n +2 2n=34 n=17 Now,the required sum of n terms, =n/2(a+l) =17/2(72+40) =17/2*112 =17*56 =952