Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
You can use this formula <span>P(AorB) = P(A) + P(B) - P(AandB)
Given:
35 LG (14 F & 21 M)
44 SB (28 F & 16 M)
Req:
- the probability that it is a female (F) or a sky blue (SB)
Sol:
</span>P(F or SB) = P(F) + P(SB) - P(F and SB)
= [(14 F + 28 F)/(35 + 44)] + [(44 SB)/(35 + 44)] - [(28 F)/(35 + 44)]
= 53.16 + 55.70 - 35.44
= 73.42%
You have to deduct 28 female parakeets from 44 sky blue parakeets because the 28 parakeets are already accounted for in the female parakeets. You can also think of how many ways you can choose a female parakeet and a sky blue parakeet. Add all female parakeets (14 + 28) = 42. Sky blue parakeet equaled to 44. Minus the 28 female parakeets included in the sky blue parakeet to avoid double counting. 42 + 44 - 28 = 58 divided by 79 (35 + 44) total parakeets = 73.42%
Answer: Yes, Sammi is correct because although it is repeating, it is expressible as a ratio of 2 integers.
I hope this helps!
Step-by-step explanation:
