Question

A well has 15 steps inside it. The water Level is at the ninth step. A frog is sitting

on the top most step. The frog jumps 3 Steps down and 2 steps up. In how many

jumps will it reach the water level?​

Answer 1

Answer:

refer to the Image for answer

Answer 2

Consider the steps as a number line

The frogs makes 3 jumps up and 2 jumps down

Upwards is positive (+)

Downwards negative (-)

The frog jumps 3 step down and 2 steps up ⇒ These are five jumps

Therefore 3 steps down = + 3  and 2 steps up = -2

+ 3 + -2

= 3 - 2

= 1

In every 3 + 2 jumps ( 5 jumps) the frog gains 1 step

If the frog is at the first step, it needs to move 8 steps to get to the 9th step

Therefore:

1 step requires = 5 jumps

8 steps requires = 5 jumps × 8 steps

= 40 jumps

Therefore the frog gets to the 9th step after 40 jumps