A B set out to meet each other from two places 165 km apart. 'A' travels 15 km the first day, 14 the second day, 13 the third day and so on. 'B' travels 10 Km the first day, 12 Km the second day, 14 the third day and so on. After how many days they will meet each other.

let they meet after n days.

since A travels 15 km first day, 14 km 2nd day, 13 km 3rd day and so on.

since it forms an AP. with first term =15 and common difference =-1

distance travelled by A in n days =

since B travels 10 km 1st day ,12 km 2nd day and 10 km 3rd day,

here it forms an AP with first term =10 and common difference =2

distance travelled by B in n days =

total distance travelled by A and B is

since n can not be negative , n=6 days

i.e. after 6 days they will meet.

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