Which number should replace the question mark?
FUNNY MATH: Which number should replace the question mark?Correct answers: 100
The first user who solved this task is Slobodan Strelac.
#brainteasers #math #riddles
ThermiteIn 1925, an ice jam was removed using thermite for the first time in the U.S. Some 250,000-tons of ice jamming the St. Lawrence River near Waddington, N.Y., broke up just hours after the reaction of three 90-lb thermite charges (a mixture of finely divided magnesium and red iron oxide, which, when ignited, gives a violent reaction that produces hot molten iron.) The method was devised by Howard Turner Barnes, of McGill University, Canada, and patented 17 Nov 1925 (U.S. No. 1,562,137). The following year he similarly helped break up an ice gorge in a stretch of the Allegheny River, at Franklin, Pa. He had studied of the properties of ice and the engineering problem of ice at intakes of hydroelectric stations on the St. Lawrence River. He succeeded (1908) Ernest Rutherford as Macdonald Professor of Physics.«[Image: Small-scale thermite reaction on ice.] |