Amanda and Fred are sister and brother. Amanda has twice as many sisters as brothers, and Fred has five times as many sisters as brothers. How many girls and boys are there in this family

In this family there are 5 girls and 2 boys

Step-by-step 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