Find the sum of the first 20 terms of the series 8, 12, 16, ....., 96

Shen16

3 years ago

8+12+16+20+24+28+32+36
+40+44+48+52+56+60+64
+68+72+76+80+84

the first 20 terms

IWTPJ

5 years ago

I'm actually confused because using the formula S = n/2 (a+l) where n=20, a=8 and l=96,

S = 20/2 (8+96)
S = 10 (104)
Hence, S = 1040

Can someone please shed more light on this?

Jnr7771

1 year ago

The answer is not there

bryanmclee

7 years ago

The selected answer is wrong because 96 was stated as the last term but was the question asked was sum of 20 terms hence it does not include the last term

aanuema

7 years ago

I support your suggestion maybe there is an error there or what?

Titilayo3491

9 years ago

sorry ans=920

Titilayo3491

9 years ago

my school y didn't u use dix method

Sn=1/2(2a+(n-1)d)

=20/2(2*8+(20-1)4)

=10(16+(19)4)

=10(16+76)

=10*92

=192