Answer:
Amy's 10 years old
Step-by-step explanation:
Clarence is ⅗ Amy's age
Isaiah is ½ Amy's age
Amy's age = ?
But summation of their age = 21
Clarence + Isaiah + Amy = 21
Let a represents Amy's age
⅗a + ½a + a = 21
Solve for a by resolving the fraction,
2.1a = 21
Divide both sides by 2.1
a = 10
Amy's 10 years old