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Odd tickets

BrainteasersEasy

A ticket roll has every odd number from $21$ to $99$ printed on it exactly once. What is the sum of all the printed numbers?

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Hint

Pair the smallest number with the largest.

Solution

There are $\frac{99 - 21}{2} + 1 = 40$ numbers.
Pairing the first with the last, the second with the next to last and so on gives $20$ pairs, each with sum $21 + 99 = 120$ .
So the total is $20 \times 120 = 2400$ .

Answer: $2400$