Question

What is the largest number you can form from the numbers $2,5,8,9,10$ and the operations $\times,+,+,-$, and exactly one pair of parentheses? For example, you can form $2 \times 5 + (9 - 8 +10) = 21$, $(2 \times 5 +9) - 10 + 8 = 17$, etc. You cannot use the parentheses for implicit multiplication, as in $10(2) = 20.$

Answer 1

The largest number is 218.

Explanation:

The given numbers are 2,5,8,9,10, given operations are ×,+,+,- and exactly one pair of parentheses.

We need to find the largest number which can be form by using given information.

We know that multiplication of two lager numbers is greater than their addition.

We need to multiply 10 and sum of 9,8,5. To get the largest number we have subtract the smallest number.

So, the largest possible number is defined by the expression

`10* (9+8+5)-2`

`10* (22)-2`

`220-2`

`218`

Therefore, the largest number is 218.