m and n are positive integers and n m. Function $ is defined as m $

Question

m and n are positive integers and n > m. Function $ is defined as m $ n = sum of all integers greater than m but less than n. What is the value of (107 $ 119)-(109 $ 120)?

A. -123
B. -2
C. 45
D. 95
E. 98

bond001 · Answer

this means the only number that matter are 108+109-119=98 (which are only in one of the numbers range)

TestPrepUnlimited · Answer

107 $ 119 = 108 + 109 + ... + 117 + 118

109 $ 120 = 110 + 111 + ... + 118 + 119.

When we subtract the bottom from the top, a lot of terms are cancelled and we are left with:

108 + 109 - 119 = 108 - 10 = 98.

Ans: E

BrushMyQuant · Answer

↧↧↧ Detailed Video Solution to the Problem ↧↧↧

https://www.youtube.com/watch?v=5nyi4jBZem8

(107 $ 119) - (109 $ 120) 
= ( sum of all integers greater than 107 but less than 119 ) - (sum of all integers greater than 109 but less than 120)
= ( 108 + 109 + ... + 117 + 118) - ( 110 + 111 + ... + 118 + 119)
= 108 + 109 - 119
= 98

So,  Answer will be E 
Hope it helps!

Watch the following video to learn the Basics of Functions and Custom Characters

https://www.youtube.com/watch?v=b7JoMX0gk8M

bumpbot · Answer

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m and n are positive integers and n > m. Function $ is defined as m $

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