Question

A boring-machine bores holes in the ground. Everytime it is turned on, it digs 9 ft into the ground. Scientists discovered that there is water at a depth of 171 ft below a certain field. How many times does the boring-machine have to be turned on to hit that water and make a well?

• A. 17
• B. 18
• C. 19
• D. 21

Answer 1

The correct option is C 19

Everytimes when boring-machine is turned on it digs 9 ft.
Depth of water level = 171 ft

So, total number of times that boring machine will be turned on to reach the water level = $\frac{171\text{ft}}{9\text{ft}}$ = 19