In the stationery shop,
13 of the books sold were Chinese books.
12 of the remaining books sold were Science books. The ratio of the number of Science books sold to the number of Math books was 9 : 5. The number of English books sold was 20. How many books were sold altogether?
Chinese |
Remaining books |
Total |
1x9 |
2x9 |
3x9 |
|
Science |
Math |
English |
|
|
1x9 = 9 u |
1x9 = 9 u |
|
|
9 |
5 |
|
|
9 u |
9 u |
5 u |
4 u |
27 u |
The number of Science books is repeated. Make the number of Science books the same. LCM of 1 and 9 is 9.
Number of English books = 4 u
4 u = 20
1 u = 20 ÷ 4 = 5
Total number of books sold
= 27 u
= 27 x 5
= 135
Answer(s): 135