PSLEThe graph shows the mass of a glass when empty and when different combinations of objects Q, R and S are placed in the glass.
- What is the mass of the empty glass?
- What is the average mass of the objects Q, R and S?
(a)
Mass of the empty glass = 150 g
(b)
Mass of Q and S
= 410 - 150
= 260 g
Mass of Q and R
= 390 - 150
= 240 g
Mass of R and S
= 370 - 150
= 220 g
(Q + S) + (Q + R) + (R + S) = 260 + 240 + 220
2 Q + 2 R + 2 S = 720
2 x (Q + R + S) = 720
Q + R + S
= 720 ÷ 2
= 360 g
Average mass of the objects Q, R and S
= 360 ÷ 3
= 120 g
Answer(s): (a) 150 g; (b) 120 g