Question

6. A certain product C is made or two ingredients A and B in the proportion of 2 -
5. The price of A is three times that of B. The
including labour charges of 80 paise per tonne. Find the cost A and B per
overall cost
of C is $5.20
per
tonne
tonne.
[Ans. $8.40, 2.80]
​

Answer 1

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6)

Given  

A certain product C is made or two ingredients A and B in the proportion of 2 : 5. The price of A is three times that of B

. The overall cost of C is ` 5.20 per tonne including labour charges of 80 paise per tonne. Find the  cost A and B per tonne.

Let the price of B per tonne = Rs x

Now price of A / tonne = Rs 3x

1 tonne of C contains 2/7 tonne of A and 5/7 of B.

Price of 1 tonne of C = 2/7 x 3x + 5/7 x x

                             = 6x / 7 + 5x / 7

                              = 11x / 7

So 11x/7 = 5.20 – 0.80

11x/7 = 4.40

So x = 4.40 x 7 / 11

So x = Rs 2.80

Therefore cost of B/tonne will be Rs 2.80

Also cost of A per tonne will be 3 x 2.80 = Rs 8.40

hope it helps....

Answer 2

Given

A certain product C is made or two ingredients A and B in the proportion of 2 : 5. The price of A is three times that of B

. The overall cost of C is ` 5.20 per tonne including labour charges of 80 paise per tonne. Find the cost A and B per tonne.

Let the price of B per tonne = Rs x

Now price of A / tonne = Rs 3x

1 tonne of C contains 2/7 tonne of A and 5/7 of B.

Price of 1 tonne of C = 2/7 x 3x + 5/7 x x

= 6x / 7 + 5x / 7

= 11x / 7

So 11x/7 = 5.20 – 0.80

11x/7 = 4.40

So x = 4.40 x 7 / 11

So x = Rs 2.80

Therefore cost of B/tonne will be Rs 2.80

Also cost of A per tonne will be 3 x 2.80 = Rs 8.40