Let the number of $1 bills that Kumar has = x
Let the number of $5 bills that Kumar has = y
Given that Kumar has twice as many $1 bills as $5 bills
mathematically,
[tex]x=2y\ldots\ldots\ldots\text{.}(1)[/tex]Given also that the total value of all of Kumar's $1 and $5 bills together is $35
mathematically,
[tex]\begin{gathered} x\times\text{ \$1 + }y\times\text{ \$5= \$35} \\ x+5y=35\ldots\ldots\ldots\text{.}(2) \end{gathered}[/tex]Solve equations (1) and (2) simultaneously using substitution method
[tex]\begin{gathered} x=2y\ldots\ldots\ldots\text{.}(1) \\ x+5y=35\ldots\ldots\ldots\text{.}(2) \\ \text{substitute }2y\text{ for }x\text{ in equation (2)} \\ 2y+5y=35 \\ 7y=35 \\ y=\frac{35}{7}=5 \\ To\text{ find x,} \\ \text{substitute 5 for y in equation (1)} \\ x=2(5)=10 \end{gathered}[/tex]Therefore, the number of $1 bills that Kumar has is 10
