I usually solve SAT questions easily and fast, but this one got me thinking for several minutes and I cannot seem to find an answer.
Here it is:
In 1995, Diana read $10$ English and $7$ French books. In 1996, she read twice as many French books as English books. If 60% of the books that she read during the 2 years were French, how many English and French books did she read in 1996?
(A) $16$, (B) $26$, (C) $32$, (D) $39$, (E) $48$
Could you please help me by either giving hints or explaining how to solve the problem?
I cannot find, in any way, the number of books of any language she read in 1996. I have tried a lot of operations with percentages, but no results.
Sorry for this question, as I am not very good at Maths.
Thank you.
Best Answer
The total number of books in the second year (call it $x$) is a multiple of $3$, so only D and E remain. Now since "60% of the total number of books" should be a whole number, we find that $x+17$ should be a multiple of $5$. Now only E remains.