Vincent has thrice as many buttons as Perry. Perry has 10 more buttons than Ian. They have a total of 90 buttons.
- How many buttons does Vincent have?
- How many buttons does Ian have?
(a)
Number of buttons that Perry has = 1 u
Number of buttons that Ian has = 1 u - 10
Number of buttons that Vincent has = 3 u
Total number of buttons
= 1 u + 1 u - 10 + 3 u
= 5 u - 10
5 u - 10 = 90
5 u = 90 + 10
5 u = 100
1 u = 100 ÷ 5 = 20
Number of buttons that Vincent has
= 3 u
= 3 x 20
= 60
(b)
Number of buttons that Ian has
= 1 u - 10
= 20 - 10
= 10
Answer(s): (a) 60; (b) 10
