Answer:
45, 36
Step-by-step explanation:
let x y minutes be the time for pipes to fill the tank, let n be the water needed to fill the tank.
x-y=9
(n/x)*20+(n/y)*20=n
n is removed by dividing the 2nd equation by n
here u get:
(1/x+1/y)*20=1
you sub x=9+y into the above equation
1/y+1/(9+y)=1/20
((9+y)+(y))*20=(9+y)(y)
180+40y=9y+y2
y2-31y-180=0
then use the quadratic formula and u will find y=36 or -5
-5 is rejected because it is negative
x=36+9=45
therefore it is 36 mins and 45 mins
Answer:
c. 22/24
Step-by-step explanation:
perimeter = 3/8 + 3/8 + 1/6
perimeter = 22/24 or 11/12
Because when you multiply by 10, it adds a zero to the end of the number, like 12*10 = 120, so vise versa for dividing
Answer: option d. the argument is valid by the law of detachment.
The law of detachment consists in make a conlcusion in this way:
Premise 1) a => b
Premise 2) a is true
Conclusion: Then, b is true
Note: the order of the premises 1 and 2 does not modifiy the argument.
IN this case:
Premise 1) angle > 90 => obtuse
Premise 2) angle = 102 [i.e. it is true that angle > 90]]
Conclusion: it is true that angle is obtuse