Answer:
She uses 243 beads for the 5th string.
Step-by-step explanation:
In this problem, we can see a pattern. If she triples the number of beads in each of the next strings, that means that we just take the last number and multiply by 3. If the first string uses 3, then:
The second uses 9, 3 * 3 = 9
The third uses 27, 9 * 3 = 27
The fourth uses 81, 27 * 3 = 81
And the 5th uses 243, 81 * 3 = 243.
