Answer:
12/35
Step-by-step explanation:
Multiply both numerators and denominators.
2/5 * 6/7
=12/35
(4-3n-5n2)
+( -2+n-3n2)
____________________
-2-2n-8n2
Answer:
18 red marbles
Step-by-step explanation:
Because the ratio of yellow marbles to red marbles is 1:6 in the population, the expected number of red marbles is 6 times the number of yellow marbles in the representative sample. there should be 18 red marbles.
Answer: 6.93 years
Step-by-step explanation:
Given
Rate of interest is 
Future value is given by 
For the investment to double itself, i.e. 

It takes around 6.93 years to double the investment.
11: 4,874 > 4,784 > 4,687
12: 8.09 > 8.057 > 8.023
13: 15.820 > 15.280 > 15.000
14: 43,628 > 40,628 > 34,628
15: 395.050 > 395.009 > 395.005