10+11+12+13+14+15+16+17+18+19+20=(10+20)+(11+19)+(12+18)+(13+17)+(14+16)+15
=30+30+30+30+30+15
=30*5+15=150+15=165
10+11+12+13+14+15+16+17+18+19+20
= (10+20)+ (11+19)+(12+18)+(13+17)+(14+16)+15
= 30+30+30+30+30+15
= 30 x 5 +15
=150+15
=165
Số số hạng là:
(20 - 10) : 1 + 1 = 11 (số)
Tổng là:
(20 + 10) × 11 : 2 = 165
Đáp số: 165.
\(10+11+12+13+14+15+16+17+18+19+20\)
\(=\left(10+20\right)+\left(11+19\right)+\left(12+18\right)+\left(13+17\right)+\left(14+16\right)+15\)
\(=30+30+30+30+30+15\)
\(=30x5+15\)
\(=150+15\)
\(=165\)
\(10+11+12+13+14+15+16+17+18+19+20\)
\(=\left(10+20\right)+\left(11+19\right)+\left(12+18\right)+\left(13+17\right)+\left(14+16\right)+15\)
\(=30+30+30+30+30+15\)
\(=30\times5+15\)
\(=150+15=165\)
10+11+12+13+14+15+16+17+18+19+20=(10+20)+(11+19)+(12+18)+(13+17)+(14+16)+15
= 30 + 30 + 30 + 30 + 30 +15
= 60 + 60 + 45
= 120 + 45
= 165
10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 = 165
Từ 10 đến 20 có 11 chữ số
Tổng là : ( 10 + 20 ) x 11 : 2 = 165
Ta có :
10+11+12+13+14+15+16+17+18+19+20
=(10+20)+(11+19)+(12+18)+(13+17)+(14+16)+15
=30+30+30+30+30+15
=30x5+15
=150+15
=165
Ta có : 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 = (10 + 20) + (11 + 19) + (12 + 18) + (13 + 17) + (14 + 16) + 15 = 30 + 30 + 30 + 30 + 30 + 15 = 30x5 + 15 = 150 + 15 = 165
Ta có : 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 = (10 + 20) + (11 + 19) + (12 + 18) + (13 + 17) + (14 + 16) + 15 = 30 + 30 + 30 + 30 + 30 + 15 = 30x5 + 15 = 150 + 15 = 165