Sarah started with 60 items in her stamp collection. each month, she buys 10 more stamps to add to her collection. the number of stamps in her collection, is given by s=10m + 60, where m is the number of months she has added 10 stamps to her collection. how many stamps will be in sarah's collection in 7 months? a. 60 b. 130 c. 167 d. 190