Please help, urgent

[EconJames]

1. Given N is a positive odd integer. If the number in the tens digit is double the digit at the units place then the value of N?
A. n>90
B. 30<N
C. N>50
D. 30<N<50
2. Given a bag which contains red and black marbles and red marbles are 5 times black marbles. If we pick 5 marbles randomly, without replacement, then
Col A: Probability of getting red marbles
col b: Probability of getting black marbles


Thanks for your help!

[julle286]

Q1:

63 works.... 21 works too.... 163 and 121 .... ?? Where is the question from? No idea...





Q2:

Lets say we have 3 black marbels and 15 red marbels --> we have 18 marbels.



Col. A: We have 18 marbels, we pick 5. If we took ALL black marbels, there are only red marbels left. So the probability is 1.

Col. B: We have 18 marbels, 3 are black. I would say its 3/18 .... ?


A is bigger.







Are my solutions correct?

[chestnut.cc]

1. 10x + y = N... x=2y... 20y + y = N... N = 21 or 63... There are 2 such solns so the ans should be 20<n<90... also they havent specified the no is a 2 digit no... so it could be anything...

2.Don't solve this... there are more red marbles... hence the probability of getting a red marble will always be higher... A

[julle286]

your' right

[EconJames]

Thanks all, I feel better now, these questions seems a little bit vague, so you help me to make sure.