Last Monday, Zeph had thrice as many cards as Harry. Today, Zeph gives 80 of his cards to his friend. Now, Harry has thrice as many cards as Zeph. How many cards does Harry have?
| |
Zeph |
Harry |
| Before |
3x3 =
9 u |
1x3 =
3 u |
| Change |
- 80 |
|
| After |
1 u |
3 u |
The number of cards that Harry had at first and in the end remains unchanged. Make the number of cards that Harry has the same. LCM of 1 and 3 is 3.
Number of cards that Zeph gives to his friend
= 9 u - 1 u
= 8 u
8 u = 80
1 u = 80 ÷ 8 = 10
Number of cards that Harry has
= 3 u
= 3 x 10
= 30
Answer(s): 30
