18 is correct...coz in the 1st hr...its climbing 3 feet and slips 2 feet back...so it has climbed 1 foot..similarly 17 hrs .....17 feet... in the 18th hr asusual it jumps 3 feet...but as it reaches the total height of the wall... i.e., it'll not slip back...so 18 is right....
i think it's 20 hours.
ReplyDeleteno....20 is wrong...try again
ReplyDelete18 hrs
ReplyDeleteIs it 7 and a half hours
ReplyDeletehey dude can u explain me how u get that 7 hours
ReplyDelete18 is correct...coz in the 1st hr...its climbing 3 feet and slips 2 feet back...so it has climbed 1 foot..similarly 17 hrs .....17 feet... in the 18th hr asusual it jumps 3 feet...but as it reaches the total height of the wall... i.e., it'll not slip back...so 18 is right....
ReplyDelete