Question

20+21+22+23+24+25+26+27+28+29+30=?

ai nhanh mk tick cho nhớ kb với mk nha

Answer 1

20 + 21 + 22 + 23 + 24 + 25 + 26 + 27 + 28 + 29 + 30

= ( 20 + 30 ) + ( 21 + 29 ) + ( 22 + 28 ) + ( 23 + 27 ) + ( 24 + 26 ) + 25

= 50 + 50 + 50 + 50 + 50 + 25

= ( 50 + 50 ) + ( 50 + 50 ) + ( 50 + 25 )

= 100 + 100 + 75

= 200 + 75

= 275

Answer 2

20+21+22+23+24+25+26+27+28+29+30

=275

Tk mk nhé

Chúc bn hok giỏi

Answer 3

20+21+22+23+24+25+26+27+28+29+30

= (20+30)+(21+29)+(22+28)+(23+27)+(24+26)+25

= 50+50+50+50+50+25

= 50×5+25

= 250+25

= 275

Answer 4

20+21+22+23+24+25+26+27+28+29+30=275