Problem number 24. In the grid, the same number is hidden under the same color square. To the right of each row, the sum of the numbers hidden under the squares in that row is given. Which number is hidden under the black square? 6, 8, 10, 12, or 14. Sometimes in a problem like this, there's an easy way to find the value of one of the numbers that is represented by a color square or a shape or a picture. We don't have that here. So let's start by looking at the row where we have the black square that we're trying to find the value of. In this row, we have a gray square, a white square, and a black square. And the sum is 32. The other two rows are made up of just gray squares and white squares. We know that one gray square and two white squares is equal to 34. And one white square and two gray squares is equal to 26. If we put these two rows together, we get three gray squares. One from the first row and two from the last row. And three white squares. Which are equal to 34 plus 26, which is 60. If three gray squares and three white squares represent a sum of 60, we can divide each side by 3 and know that one gray square plus one white square is equal to 60 divided by 3, or 20. This will enable us to finish solving the problem. Because in the middle row, we have just one gray square and one white square. We don't need to figure out how much each one of these is. We know that these two together are equal to 20. So we know that 20 plus the black square is equal to 32. If we put in 12 for the black square, this sum is true. So the answer is D, 12.

grid puzzle

hidden number

row sums

equation solving

black square