Dylan and Andy have some red pens and some white pens. The number of white pens Dylan has is equal to the number of red pens Andy has.
15 of Dylan's pens are red and
34 of Andy's pens are white. There are a total of 30 red pens. Find the total number of pens they have.
| Dylan |
Andy |
Total |
| Red |
White |
Red |
White |
|
| |
1x4 |
1x4 |
|
|
| 1x1 |
4x1 |
1x4 |
3x4 |
|
| 1 u |
4 u |
4 u |
12 u |
21 u |
The number of Dylan's white pens and Andy's red pens is the same.
The number of Dylan's white pens is repeated. The number of Andy's red pens is repeated. Make the number of Dylan's white pens and Andy's red pens the same. LCM of 4 and 5 is 4.
Number of red pens
= 1 u + 4 u
= 5 u
5 u = 30
1 u = 30 ÷ 5 = 6
Total number of pens
= 1 u + 4 u + 4 u + 12 u
= 21 u
= 21 x 6
= 126
Answer(s): 126
