Mary bought
35 as many notebooks as correction tapes at first. After she bought another 20 notebooks and 60 correction tapes, there were
25 as many notebooks as correction tapes. How many notebooks and correction tapes did Mary buy at first?
| |
Make p the same
(1)x5 = (3) |
Notebooks
(1) |
Correction Tapes
(2) |
Make p the same
(2)x2 = (4) |
| Before |
15 u |
3 u |
5 u |
10 u |
| Change |
+ 100 |
+ 20 |
+ 60 |
+ 120 |
| After |
10 p |
2 p |
5 p |
10 p |
Make p the same.
(3) = (4)
15 u + 100 = 10 u + 120
15 u - 10 u = 120 - 100
5 u = 20
1 u = 20 ÷ 5 = 4
Number of notebooks and correction tapes that Mary bought at first
= 3 u + 5 u
= 8 u
= 8 x 4
= 32
Answer(s): 32
