Machine A can produce x products in 1 hour, machine B can produce x products in 3 hours. If machine A and B work together to produce x products, what is the ratio if the products that the faster machine can produce, to the total products?
A. 1/4
B. 1/2
C. 3/4
D. 1
E. 5/4
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Ax products  1 hr
B x products  3 hrs or x/3 products in 1 hr
A+B  1 hr  (x + x/3) products = 4x/3 products
A+B  4x/3 products  1 hr
Therefore A+B  x products  [1/(4x/3)]*x = 3/4 hr
In 3/4 hr A would make 3x/4 products
Hence ratio = (3x/4)/x = 3/4
Hence C
B x products  3 hrs or x/3 products in 1 hr
A+B  1 hr  (x + x/3) products = 4x/3 products
A+B  4x/3 products  1 hr
Therefore A+B  x products  [1/(4x/3)]*x = 3/4 hr
In 3/4 hr A would make 3x/4 products
Hence ratio = (3x/4)/x = 3/4
Hence C