There is a line with 10 dots and another line with 8 dots. Find the possible no. of triangles.

• TWO CASES WILL ARISE
  
  CASE 1: SELECTING 2 DOT FROM 10 DOTS AND SELECTING 1 DOT FROM 8 DOT
  C(10,2)*C(8,1)=360
  
  CASE 2: SELECTING 2 DOT FROM 8 DOTS AND 1 DOT FROM 10 DOTS
  C(8,2)*C(10,1)=280
  
  sO,TOTAL = 360+280=640.
• 11 years agoHelpfull: Yes(60) No(0)
• Ans. 640
  Thought process:
  Select any three points from all total 18 dots and then subtract those triangles formed with co-linear points.
  It will be (10+8)C3-(10C3+8C3)=640.
• 11 years agoHelpfull: Yes(18) No(0)
• 10c2*8c1+8c2*10c1=640
• 11 years agoHelpfull: Yes(8) No(0)
• sorry for last answer;
  640 is right answer;
  18c3-10c3-8c3=640;
• 11 years agoHelpfull: Yes(5) No(0)
• CASE 1: SELECTING 2 dots FROM 10dots line AND SELECTING 1 DOT FROM 8dots line
  10C2 * 8C1 = 360
  
  CASE 2: SELECTING 2 dots FROM 8dots line AND 1 DOT FROM 10dots line
  8C2 * 10C1 = 280
  
  ans = 360+280=640
• 11 years agoHelpfull: Yes(4) No(0)
• 18c3-10c3-8c3
• 11 years agoHelpfull: Yes(3) No(1)
• Ans:1048;
  18c3-10c3-8c3=1048;
• 11 years agoHelpfull: Yes(0) No(6)
• we can select 2 points from one line and 1 from other line
  so total ways 10c2*8c1+10c1*8c2
  =360+280
  =640
• 11 years agoHelpfull: Yes(0) No(0)