Aarti bought a ribbon that was 2.56 m long. She glued some pink and yellow flowers alternately from the beginning to the end of the ribbon at equal intervals of 8 cm. If the first flower she glued was yellow, how many yellow flowers did she use?
(a) 16
(b) 17
(c) 15
(d) 18
Answer is 17; she started with yellow and put 32 more flowers, alternate yellows