If LL = 60 and PL = 20, what is PI?

If LL = 60 and PL = 20, what is PI?

• A. 60
• B. 20
• C. 40
• D. 80

Answer: (C)

On a straight line with a point between the others, the distance from the far points equals the sum of the two segments to the middle point. Here I, P, and L lie on a line with P between I and L, so IL = IP + PL. You’re given IL = 60 and PL = 20, so IP = IL − PL = 60 − 20 = 40. Therefore PI is 40.

On a straight line with a point between the others, the distance from the far points equals the sum of the two segments to the middle point. Here I, P, and L lie on a line with P between I and L, so IL = IP + PL. You’re given IL = 60 and PL = 20, so IP = IL − PL = 60 − 20 = 40. Therefore PI is 40.