If A:B is 7:5, B:C is 3:4 and C is 30 then what is the value of A?

• A/B=7/5,
  B/C=3/4,C=30
  B=90/4
  4A/90=7/5
  A=630/20
  A=31.5
• 10 years agoHelpfull: Yes(8) No(0)
• A:B = 7:5 = 21:15 & B:C = 3:4 = 15:20
  Then A:B:C = 21:15:20
  Hence A:C = 21 : 20
  A = 21 * 30 / 20
  A = 31.5
• 10 years agoHelpfull: Yes(3) No(0)
• because A:B=7:5 let a=7x and b=5x
  and B:C=3:4 let b=3y and c=4y
  hence 4y=30
  => y=15/2
  hence b=45/2
  hence 5x=45/2
  i.e. x=9/2
  so A=7x=63/2 = 31.5
• 10 years agoHelpfull: Yes(1) No(0)
• b:c=3:4
  ie b/30=(3/4)
  b=(45/2)
  .
  . . a=(63/2)
• 9 years agoHelpfull: Yes(0) No(0)
• 5A=7B.......(1) 4B=3C=3*30=90,B=90/4 PUT VALUE EQ.......1,A=7*90/20=31.5
• 9 years agoHelpfull: Yes(0) No(0)
• three boxes can be arranged in 3! ways and favorable conditions is only 1
  so answer is 1/6
• 8 years agoHelpfull: Yes(0) No(1)
• above all answers are wrong
  here the formula is a+b+(ab)/100= 20+10+200/100= 32%
• 8 years agoHelpfull: Yes(0) No(2)
• B:C::3:4 =>3C=4B
  with c=30 then B=90/4 =>22.5
  
  A:B::7:5 =>7B=5A
  with b=22.5 => A=31.5
• 7 years agoHelpfull: Yes(0) No(0)