Answer:
In this family there are 5 girls and 2 boys
Explanation:
Fred has five times as many sisters as brothers, so at least he has five sisters.
1. Let's suppose Fred has just one brother, in this case he would have five sisters (including Amanda). The condition that Fred has five times as many sisters as brothers is fufilled.
2. If Fred has one brother, it means that Amanda has two brothers
3. If Fred has five sisters (including Amanda), it means that Amanda has four sisters.
4. If Amanda has two brothers and four sisters, the condition that she has twice as many sisters as brothers is fufilled.
5. Then, in both cases, there are 5 girls and 2 boys:
Fred + 1 brother + 5 sisters = 2 boys, 5 girls
Amanda + 2 brothers + 4 sisters = 2 boys, 5 girls