Answer:
20, 90 and 100
Step-by-step explanation:
Total number of statues = 210
Assuming that a large statue = x, medium statue = y and a small statue = z
Then, x + y + z = 210........i
Also, we're told that the monthly cost is $760, so
5x + 4y + 3z = 760.........ii
Cost of selling is $3640, so then
26x + 18y + 15z = 3640.........iii
Solving i and ii simultaneously, we have
5x + 5y + 5z = 1050
5x + 4y + 3z = 760
Subtracting, we have
y + 2z = 290.........iv
Again, solving ii and iii simultaneously, we have
130x + 104y + 78z = 19760
130x + 90y + 75z = 18200
On subtracting, we have
14y + 3z = 1560.........v
And finally, solving iv and v simultaneously, we also have
14y + 28z = 4060
14y + 3z = 1560
On subtracting,
25z = 2500
z = 2500 / 25
z = 100
Substituting for z = 100 in iv, we have
y + 2(100) = 290
y + 200 = 290
y = 290 - 200
y = 90
Substituting for y = 90, and z = 100 in i
x + 90 + 100 = 210
x + 190 = 210
x = 210 - 190
x = 20
Therefore, large statues has to be 20, medium statues has to be 90, and small statues has to be 100
