Question

A ditch contains 10 centimeters of water. Rainwater accumulates in the ditch as follows: 10 centimeters of water in the 1st second, 15 centimeters in the 2nd second, 20 centimeters in the 3rd second, and so on. Assuming that the ditch has sufficient capacity for storage, how many centimeters of water will it have after 10 seconds?
a.
55
c.
75
b.
65
d.
110