Subject: Math
Name: Mary
Who are you: Student

I have four two-digit numbers written on my paper. The sum of these 4 numbers is less than 100.

True or False - each number is less than 25

If all the numbers on my paper are different, what is the largest (two-digit) number I could possibly have written.


Hi Mary.

Is each number less than 25? Try it: 25 + 12 + 13 + 14 < 100, so no this is not necessarily the case.

What is the largest 2-digit number? Let's assume that a two-digit number cannot begin with 0, to begin. What is the largest sum less than 100? It's 99.
So we want the largest 2 digit number that, when added to the smallest three different 2 digit numbers, gives 99. If you can decide what are the lowest 2 digit numbers and subtract them all from 99, you can find the answer to this question.

Stephen La Rocque.>