Machine-translated by Google. Questions are authored in English.
Top

Discussion

Find the value of question mark (?) in the following :

\[ \begin{aligned} &1\tfrac{3}{4} + 5\tfrac{1}{8} \\ &- (?) \times \tfrac{4}{3} \div 2\tfrac{2}{3} \\ &= 5\tfrac{3}{4} \end{aligned} \]

  • A.\(3\frac{1}{2}\)
  • B.\(3\frac{1}{4}\)
  • C.\(2\frac{1}{4}\)
  • D.\(5\frac{3}{4}\)

Answer: C

The missing value is \(2\frac{1}{4}\).

Follow BODMAS: the multiplication and division on (?) come before the addition and subtraction. First the known terms:

\[ \begin{aligned} 1\tfrac{3}{4} + 5\tfrac{1}{8} &= \tfrac{14}{8} + \tfrac{41}{8} = \tfrac{55}{8} \\ \tfrac{4}{3} \div 2\tfrac{2}{3} &= \tfrac{4}{3} \times \tfrac{3}{8} = \tfrac{1}{2} \end{aligned} \]

So \(\tfrac{55}{8} - \tfrac{1}{2}(?) = 5\tfrac{3}{4} = \tfrac{46}{8}\), giving \(\tfrac{1}{2}(?) = \tfrac{9}{8}\) and \((?) = \tfrac{9}{4} = 2\tfrac{1}{4}\).

The other options do not satisfy the equation; for example \(3\frac{1}{2}\) would make the left side \(5\frac{1}{8}\).

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.