1. There are 4 people in the family. If Masha's scholarship is doubled, the total income of the entire family will increase by $5 \%$, if instead, Mom's salary is doubled - then by $15 \%$, if Dad's salary is doubled - then by $25 \%$. By what percentage will the family's total income increase if Grandpa's pension is doubled?
1. The first method. If Masha's scholarship is doubled, the family income will increase by the amount of this scholarship. Therefore, Masha's scholarship constitutes $5 \%$ of the total income. Similarly, Mom's salary is $15 \%$, and Dad's is $25 \%$. The remaining share $100 \% - 5 \% - 15 \% - 25 \% = 55 \%$ is attributed to Grandpa's pension. Thus, if his pension is doubled, the family's total income will increase by $55 \%$.

The second method. If all family members suddenly started getting paid twice as much, the total income would increase by $100 \%$. Out of this increase, $5 \%$ is attributed to Masha, $15 \%$ to Mom, $25 \%$ to Dad, and the remaining $55 \%$ to Grandpa.