Multiplying a 2-significant-figure number by a 4-significant-figure number and then dividing the product by a seven-significant-figure number yields a number with how many significant figures?
A)6/7
B)1
C)2
D)13
E)8/7

Question

Multiplying a 2-significant-figure number by a 4-significant-figure number and then dividing the product by a seven-significant-figure number yields a number with how many significant figures?
A)6/7
B)1
C)2
D)13
E)​8/7

Quizplus · Accepted Answer

When multiplying, the number of significant figures in the result is equal to the number of significant figures in the factor with the least number of significant figures. In this case, the 2-significant-figure number is the limiting factor. When dividing, the number of significant figures in the result is equal to the number of significant figures in the divisor. Therefore, the result will have 7 significant figures (the same as the divisor). However, since the product only has 2 significant figures, we must round the result to 2 significant figures, giving us a final answer with 2 significant figures.

Multiplying a 2-Significant-Figure Number by a 4-Significant-Figure Number and Then