PSLEThe graph shows the mass of a glass when empty and when different combinations of objects J, K and L are placed in the glass.
- What is the mass of the empty glass?
- What is the average mass of the objects J, K and L?
(a)
Mass of the empty glass = 180 g
(b)
Mass of J and L
= 420 - 180
= 240 g
Mass of J and K
= 410 - 180
= 230 g
Mass of K and L
= 430 - 180
= 250 g
(J + L) + (J + K) + (K + L) = 240 + 230 + 250
2 J + 2 K + 2 L = 720
2 x (J + K + L) = 720
J + K + L
= 720 ÷ 2
= 360 g
Average mass of the objects J, K and L
= 360 ÷ 3
= 120 g
Answer(s): (a) 180 g; (b) 120 g