Assume that y varies directly as x then solve. If x = 12 when y = 15 find x when y = 21.
2 answers:
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Answer: 28 %
Step-by-step explanation:
Let, Initially,
V be the volume of construction work
r be the productivity of labor
n be the number of days
x be the number workers.
Thus, V = r × n × x ------------(1)
Now, According to the question,
The volume of construction work was increased by 60% but the productivity of labor increased by only 25%.
Therefore,
Final volume of the work = 160% of V = 1.6 V
Final productivity = 125% of r = 1.25 r
Also, the time is same in both conditions,
Final time taken = n
Let y be the number of people after changes.
Thus, 1.6 V = 1.25 r × n × y -----(2)
Dividing equation (1) by equation (2)
We get, y = 1.60 x/1.25
Thus, the changes in the number of workers
=
= 0.28 × 100
= 28 %