Answer:
Answer C
Explanation:
Let the number be x
(30/100)*(20/100)x = (600 / 10000)x = 0.06 x
(40/100)*(y/100)*x = 0.06 x You are solving for y
40y/10000x = 0.06 x Divide both sides by x
40y / 10000 x/x = 0.06 x/x The xs disappear
40 y / 10000 = 0.06 Multiply both sides by 10000
40 y = 0.06 * 10000
40y = 600 Divide by 40
y = 600 / 40
y = 15
Answer C