Which explanation best describes how to solve this problem?

tanya used 170 gold stars and 140 silver stars to decorate 10 cards. she put the same number of stars on each card.

how many stars did tanya put on each card?

a.
add 170 and 140 together and subtract 10.

b.
add 170 and 140 together and divide by 10.

c.
divide 170 by 10 and add 140.

d.
divide 140 by 10 and add 170.