80(miles) x 52(weeks in a year) = 4160(miles in a year)
4160 / 4(tunes in a year) = 1040(miles to go before a tune)
Now for Christine
100(miles) x 52(weeks in a year) = 5200(miles in a year)
5200 / 1040(miles to go before a tune) = 5(tunes in a year)
Answer C. 5
