400 consecutive multiples of 5 and 600 consecutive multiples of 4 are

Question

400 consecutive multiples of 5 and 600 consecutive multiples of 4 are selected. What is the ratio of odd to even numbers in the selected numbers?

(A) 1 to 5
(B) 1 to 4
(C) 4 to 1
(D) 5 to 16
(E) 5 to 17

akhiparth · Answer

B...1 to 4 since every other multiple of 5 is even...So effectively we have odd/even as 200/800

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mskx · Answer

1) 400 consecutive multiples of 5: half of them are odd
2) 600 consecutive multiples of 4: all of them are even

Thus, 200 (odd)/800 (even) = 1/4  B

bunny12345 · Answer

E ?
We have to remove the common terms and then count. Numerator comes out to be 200 and denominator comes out to be 680 (200+ {600-120}).
Hence 200/680 = 5/17

catghosh · Answer

The list of multiples of 5 selected is: 5,10,15,20,.......2000.

Here, the list can be broken up into list containing odd no.s and list containing even no.s

List containing even no.s from the list of multiples of 5 : 10,20,.....,2000. 
The number of even no.s in this list is   + 1 ....according to the A.P. series formula. 
It is = (2010/10)+1 = 202

List containing odd no.s from the list of multiples of 5 : 5,15,....1995.
The no. of odd no.s = (2000/10) +1 = 201

We have another list of the multiples of 4 : 4,8,12,....,2400.
All no.s in this list are even. 
No. of numbers in this list = (2404/4)+1 = 602

Thus, Odd/Even = 201/(202+602) = 1/4 
Answer is B.

ScottTargetTestPrep · Answer

Half of the 400 multiples of 5 are even and the other half are odd. So we have 200 even multiples of 5 and 200 odd multiples of 5.

All the 600 multiples of 4 are even.

Thus we have 200 odd numbers and 200 + 600 = 800 even numbers, and the ratio of odd numbers to even numbers is 200/800 = 1/4.

Answer: B

Maneeshagr · Answer

How do you figure that consecutive numbers have common multiples. Lets say for five consecutive number starts from 5 upto 2000 and for four it starts from 2004 upto 4400.
Than answer would be B.
Correct me if I am wrong please.

GMATBusters · Answer

400 consecutive multiples of 5 are 5,10,15,20...
so there will be 200 ODD numbers and 200 EVEN numbers.

all 600 consecutive multiples of 4 are EVEN.
But out of these 600 multiples, 600/5 = 120 are also multiples of 5 (even).

so total no of odd numbers = 200
and total number of even numbers = 200+600-120 (120 is subtracted because these 120 numbers have been counted twice)
 = 680

Required ratio = 200/680 =5/17

Answer = E

Ratnaa19 · Answer

What’s the correct answer?

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bunny12345 · Answer

I know that the language is a bit confusing. If we could take any consecutive numbers then 2 possible scenarios may arise. Either we take some repeating numbers or we don't. But if we take only the immediate consecutive ones(starting from 4 and 5 respectively) then we have only one way of solving the question, which is obviously taking out the common ones. Fingers crossed.

Lets wait for OE and OA

400 consecutive multiples of 5 and 600 consecutive multiples of 4 are

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