Okay so, you need to have to numbers that when added together make exactly 100. I figured this out mentally but there is probably a way to do this with an actual equation. Anyways the only number that you can have three times as much without going over 100 when you add the first number is 25,
So, like if you set it up so A=pens B=pencils
A*3 must equal B and A+B must equal 100.
The only number that fits that description is 25 (25 would be your A) because 3 times as much as 25
equals 75(this would be your B). And since you need to add the 25(the a) to 75(the b) It equals 100!
so to recap
25pens+75pencils=100utensils
To find out how many more pencils than pens he has you would just subtract them. So
75pencils-25pens=50
Tom has 50 more pencils than pens.
Do you understand how I did this?
