Grapes!

Problem:




Solution:

1st, we try to figure out how many percent of the grapes are red.

We know 30% are green, and all the grapes are either red or green, so 100% - 30% = 70% of the grapes are green.

Next, we try to figure out how many red grapes should she use.

We have 70% of 60 grapes are red, so we have $ 60 \times \frac{70}{100} = 42 $ red grapes!

So your answer is correct, yay!