Brain Teasers
Scratch Test
What letter completes the following series? Why?
T, G, C, F, A, O, Q, T, C, ?
T, G, C, F, A, O, Q, T, C, ?
Answer
DThese are the first letters of the minerals that make up Mohs Scale of Mineral Hardness (talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, diamond).
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