The psychrometer is a device used to measure the
Relative Humidity (RH) of the air.
Relative humidity is the ratio of
(the amount of moisture in the air, here and now)
to
(the amount of moisture the air could hold at this temperature) .
Being a ratio, it has no units. It's just a naked number, always
less than ' 1 ', and usually expressed as a percent.
Answer:
20% of number 1 to 70 has one or nine in it
Explanation:
20% numbers from 1 to 70 have 1 or 9 in the unit's digit. 1,9,11,19,21,29,31,39,41,49,51,59,61,69 this is that series of numbers .These are total 14 numbers out of 70 so 14/70×100 gives us 20 % occurrence of 1 or 9 at unit place.
Cutting down the trees! (Stop cutting them down)
And human presence disrupting the ecosystem (let the environment be)