9 machines of model A and 5 machines of model B working in a day to print 905 bucks.
Solution:
Given that
Model A can print 70 bucks per day
Model B can print 55 bucks per day
Total number of printing presses = 14
Total number of bucks printed by machines of Model A and Model B in 1 day = 905
Let assume number of printing presses of model A = "y"
As total 14 printing presses are there and "y" are of model A, so remaining that is (14 – y) will be of model B.
Number of bucks printed by 1 machine of model A in one day = 70
So number of bucks printed by "y" machine of model A is given as:
![\begin{array}{l}{=y * \text { Number of bucks printed by } 1 \text { machine of model } \mathrm{A} \text { in one day }} \\\\ {=y * 70=70 \mathrm{y}}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ippgx9xt4stfzgm0twkb8ur8t7hejz8af5.png)
Number of bucks printed by 1 machine of model B in one day = 55
So number of bucks printed by (14 –y) machine of model B is given as:
![\begin{array}{l}{=(14-y) * \text { Number of bucks printed by } 1 \text { Machine of model } B \text { in one day }} \\\\ {=(14-y) * 55=770-55 y}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/o3anj1wx4h068ia6fnz1s6q918jjw64cag.png)
Also given that Total number of bucks printed by machines of Model A and Model B in 1 day = 905
Total number of bucks printed by machines of Model A and Model B in 1 day = number of bucks printed by "y" machine of model A + Number of bucks printed by (14 –y) machine of model B
![\begin{array}{l}{=>905=70 \mathrm{y}+(770-55 \mathrm{y})} \\\\ {=>905=70 \mathrm{y}+770-55 \mathrm{y}} \\\\ {=>905-770=70 \mathrm{y}-55 \mathrm{y}} \\\\ {=>135=15 \mathrm{y}} \\\\ {=>\mathrm{y}=(135)/(15)=9}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/emuhrrchubdly418kyxh7t1njnuh3er29o.png)
Number of printing presses of model A = y = 9
Number of printing presses of model B =(14- y) = 14 – 9 = 5
Hence 9 machines of model A and 5 machines of model B working in a day to print 905 bucks.