Problem Solving

Question Number 16:
If the sales for the month of June follows the same trend as for April to May, the sales of single glazing, triple glazing, and wood embedded will increase by 5000 and the sales for double glazing and UPVC glazing will decrease by 10000.

Hence, the difference in total sales of May and June = 2*10000 - 3*5000 = 20000 - 15000 = 5000

The correct answer is A.

Question Number 17:
Refer to the following table for the total sales in January, February, and April.


Hence, required ratio = (285 + 290)/230 = 575/230 = 5/2

The correct answer is E.

Question Number 18:
Let us assume, the sales for single glazing and double glazing in December of previous year was S and D, respectively.

Hence, sales of single glazing in January = S - 20% of S =(0.80)*S = 40,000 ---> S = 40,000/0.8
And, sales of double glazing in January = D + 40% of D =(1.40)*D = 100,000 ---> D = 100,000/1.4

Hence, required ratio = S/D = (40,000/0.8)/(100,000/1.4) = (4*14)/(10*8) = 7/10 = 0.7

Clearly none of the options are correct in their given form.
Let us check for the closest answer we can get...

• A. 2/5 = 0.4
  B. 1/2 = 0.5
  C. 3/5 = 0.6
  D. 5/7 = 0.71...
  E. 4/5 = 0.8

We see that D is the closest to 0.7 we can get.

The correct answer is D.

madeleine.lapierre wrote:For the third question I thought the answer was 5:7 as [40000/(1-0.2)]: [100000/(1+0.4)] is roughly equal to 50000:71000.. I could be completely wrong though.

Thank you for pointing out that we can approximate the actual answer to select the best answer. I've modified my reply accordingly.

However, I believe in GMAT if you come across such a question they will either include the exact answer in the options or ask to find out the approximate ratio.

pirrum wrote:Would it possible to look at my other post? As those one's I find worse!

I've looked into them. But I found they are ambiguous and poorly constructed questions.