Courses
Courses for Kids
Free study material
Offline Centres
More
Store

# Make up as many expressions with numbers (no variables) as you can from three numbers 5, 7 and 8. Every number should be used not more than once. Use only addition, subtraction and multiplication.

Last updated date: 20th Jun 2024
Total views: 404.1k
Views today: 11.04k
Verified
404.1k+ views
Hint: In this question three numbers are given and by using these three numbers and applying addition, subtraction and multiplication between them we have to create the possible mathematical expressions with every number used only once. Since there are 3 numbers so the total number of possible combinations would be $3! = 6$ but there are also 3 operation signs that need to be filled between numbers so by alternating the position of the operation signs as well as the position of the numbers there are so many possible combinations.

$5 + 7 - 8\\ 5 + 7 \times 8\\ 5 - 7 + 8\\ 5 - 7 \times 8$
$5 \times 7 + 8\\ 5 \times 7 - 8\\ - 5 + 7 \times 8$
$7 + 5 - 8\\ 7 + 5 \times 8\\ 7 - 5 + 8\\ 7 - 5 \times 8$
$8 + 5 - 7\\ 8 + 5 \times 7\\ 8 - 5 + 7\\ 8 - 5 \times 7$
Note: It should be noted that the expressions that have the same value but have the difference in the operation sign position and the position of the number are not considered as the different expressions. For example, the value of the expression $5 + 7 + 8$ has the same value as the expression $8 + 5 + 7$ but the position of the numbers is different, therefore these expressions are not considered different expressions and they are counted as one.