Zara has forgotten her 4-digit PIN code. She knows the first digit is a factor of 20 and the 4 digits make a number divisible by 5.
How many different sets of 4 digits could it be?

answer: a.   one is a factor of every whole number since every number is divisible by itself.

14

step-by-step explanation:

14 x 3 = 42

large crystals result from very slow cooling.

evaporation of water: this would produce an evaporite which is a sedimentary rock. like a salt pan in a desert. not possible to have volcanic rocks originate this way.

crystalization in molten earth: slow cooling over time. (hundreds to millions of years)

crystalization at earth's surface: this results in fast cooling. (a few hours to a few months or years)

crystalization from cooling off hot water: that would be a hydrothermal deposit. while associated with volcanics they are not volcanic rocks themselves and usually occur fairly rapidly.