In a mixture of three varities of pulses , the ratio of their weight is 4 : 5 :
8. If 5 kg of pulses of the first variety, 10 kg of the second variety and
some quantity of pulses of the third variety are added to the mixture ,
the ratio of the weights of three varieties of pulses becomes as 5 : 7 : 9 .
in the final mixture , find the quantity of third variety of pulses was : ?
(A) 42 (B) 48 (C) 40 (D) 45

• (D) 45 Kg
  
  Let the initial quantity of the three varieties of pulses be 4x, 5x and 8x respectively, then
  (4x+5)/(5x+10)=5/7 or 28x+35=25x+50, x=5
  Now if 'y' kg of pulses are added to third variety, then comparing the ratio of second and third variety
  (5x+10)/(8x+y)=7/9
  On substituting value of x=5, (25+10)/(40+y)=7/9 or 315=280+7y ,y=5
  So total quantity of third variety of pulses=8x+y=8*5+5=45
• 8 years agoHelpfull: Yes(0) No(0)
• observe the ratios before and after in first variety adding 5 kg increased the ratio from 4 to 5 and in second variety adding 10 kg increased the ratio from 5 to 7 so each part is 5 kg so as third ratio increased from 8 to 9 the third variety of pulses is 9*5=45kg
• 8 years agoHelpfull: Yes(0) No(0)