Let the least value be x. Then the next value is x + 20 and the next value is x + 40 and so on. According to question (x)+(x+20)+(x+40)+(x+60)+(x+80)+(x+100)+(x+120)=700 ⇒ 7x+(20+40+60+80+100+120)=700 ⇒ 7x+20(1+2+3+4+5+6)=700 ⇒ 7x+20×21=700 ⇒ 7(x+60)=7(100)⇒x=40