A is the right answer ( I say) because 1 over 4 if you times it with 2 you get 1 over 8
Your welcome I hope this works for u
Answer:
<h2>18mins</h2>
Step-by-step explanation:
This problem is on combined work rate
given that
Marta can vacuum the house in 30 min
then her rate= 1/30
Also, her daughter will take 45 min to vacuum the house
her daughter's rate will be = 1/45
then the combined work rate is
1/30+1/45=1/T
30+45/30*45=1/T
75/1350= 1/T
1/18=1/T
This means that they will both take 18 minutes working together to vacum a house
Y = 3x
so
if x = 5 then y = 15
if x = 10 then y = 30
so a = 10 and b = 15
answer is B. second choice
a = 10 and b = 15