Question

Three siblings - Sarah and kate- commited themselves to volunteer 130 hours for a homeless charity to build a new housing. Kate worked 15 hours more than Sarah . Dave worked 5 hours fewer than Sarah. How many hours did each sibling volunteer?

Answer 1

Given

Three Sibblings

130 h for a homeless charity

Kate work 15 hours more than Sarah

Dave work 5 hours fewer than Sara

Procedure

K : kate

D : Dave

S : Sarah

Equations

`\begin{gathered} K=S+15 \\ D=S-5 \\ K+S+D=130 \end{gathered}`

Solution

`\begin{gathered} S+15+S+S-5=130 \\ 3S+15-5=130 \\ 3S+10=130 \\ 3S=130-10 \\ 3S=120 \\ S=(120)/(3) \\ S=40 \end{gathered}`
`\begin{gathered} K=40+15 \\ K=55 \\ \\ D=40-5 \\ D=35 \end{gathered}`

K : kate 55 hours

D : Dave 35 hours

S : Sarah 40 hours