Answer:
Step-by-step explanation:
Well, the ratio of yellow beads to blue beads is 4:5. The best way I think is to guess and check multiplying the ratio by integers. You need between 15 and 20.
4 : 5 ( = 9 too little )
8 : 10 ( = 18 just right)
12 : 15 ( = 27 too much)
So per necklace, 8 yellow beads and 10 blue beads would be needed.
I hope this helps :-)
Answer:
84
Step-by-step explanation:

time= distance/speed
take distance as d. take time as t.
the time taken: d/ 65 for the train however it is the same distance for d/130 so we can say (d/65)-3 = d/130
now solve the equation, multiply both sides by 130
2d-390=d
2d-d=390
so d=390 mi