(01/07/97) *************************************** MathMagic Cycle 23: Level 10-12 Regular *************************************** Patterns 1) Without the aid of algebra, try to find a two digit number that is twice the sum of its digits. 2) A sequence of figures is built as follows: x x xxx x xxx xxxxx etc... Fig.1 Fig.2 Fig.3 How many "x" are there in figure 100? 3) For this pattern: 1 + 2 = 3 4 + 5 + 6 = 7 + 8 9+ 10 + 11 + 12 = 13 + 14 + 15 ... What is the last number in the 80th row going to be? **************************************** MathMagic Cycle 23: Level 10-12 Advanced **************************************** 1) If the natural numbers are arranged in a triangular grid (see below), what is the third number in the 50th row? 1 2 3 4 5 6 7 8 9 ... 2) What is the last digit of this exponent? 1992 3 3) What is the last digit of the product of these exponents? 1988 1988 1988 2 X 3 X 7 Remember MathMagicians: share your thoughts with us. ============================ Good luck MrH