, 2016

Solution 1

Since Alex pays 2.25 to take the bus, then 20 trips on the bus would cost Alex $20\times$ \$2.25=\$45$.

Since Sam pays 3.00 to take the bus, then 20 trips on the bus would cost Sam $20\times$ \$3.00=\$60$.

If they each take the bus 20 times, then in total Alex would pay $\$60-\$45=\$15$ less than Sam.

Solution 2

Since Alex pays 2.25 to take the bus, and Sam pays 3.00 to take the bus, then Alex pays $\$3.00-\$2.25=\$0.75$ less than Sam each time they take the bus.

If they each take the bus 20 times, then in total Alex would pay $20\times \$0.75=\$15$ less than Sam.