The frog riddle (Use your maths)

18 I think! But then my maths is getting a little rusty these days!

16 jumps because on the last jump he will jump 3 feet to the top but will not fall back, as he is at the top

Can't be 16,

He goes forward 3 and backward 2 (so he only moves forward 1 at a time)

After 15 jumps he's 15ft up the well. On the 16th he moves forward to 18 then back to 16. On the 17th jump he moves forward to 19 (not quite out!) but back to 17ft. Then on the 18th jump he reaches 20ft, thus OUT of the well!!

you are taking into account the bottom foot of the well, he is already on the bottom so you don't count the bottom foot and then he will be 3 feet from the top at 17 hops so i was wrong lol but it is 17 jumps

Hmmmm I get 19

and i'm a dick, you're right lol i WAS counting the bottom as 1 foot sorry and many apologies

No whay you are right it is 17, my excuse is I've been up all night drinkin

Hang on here....... he jumps 3ft up to begin..... thus at 3ft high, but slips 2ft to end at 1ft after first jump.

Thus he travels 1ft up at the conclusion of each jump. After 15 jumps he's on 15ft, 16 jumps its up to 18 but down to 16, 17 jumps its up to 19 but down to 17 and the 18th jump he reaches 20ft (the height of the well)

If you want to be really fussy you could say he hasn't CLEARED the well at 20ft, and thus he needs to jump once more (which is 19!)

Personally I think he made it at 18!!

on the 17th Jump the frog jumps up to 20ft and falls back to 18ft.

on the 18th Jump he jumps up to 21ft (and therefore is out of the well)

The answer is 18 jumps.

FOLKS it's 18 jumps.

When he is at 18ft and jumps 3 feet. 3 + 18 = 21ft.

Cleaired the well.

Kedge, when the frog is at 17 feet (17 jumps) and his next jump is 3 feet, why isnt he out?

Why does he have to get 1ft ABOVE the well to clear it?

Henrythe8, it depends where you measure the hight from. If it is the bottom of the frog, then on the 17th jump he would be sitting on the top of the well.

If you measure from the top of the frog, then at the pinacle of the 17th jump the top of him has reached 20ft. but he has not cleared the well.

WHY at 20 ft he's out. isn't he?

how can he get out if only the top of his head is at 20ft? surely the frog will need to get his legs up to 20ft before he can get out?

Jump Ft highest
1 1 3
2 2 4
3 3 5
4 4 6
. . .
. . .
16 16 18
17 17 19
18 (18) 20
19 out 21

The answer depends on whether you class reaching 20 as out or going OVER 20 as out!

Either way, the answers are 18 or 19!!!