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 = 180 g
(b)
Mass of Q and S
= 460 - 180
= 280 g
Mass of Q and R
= 530 - 180
= 350 g
Mass of R and S
= 510 - 180
= 330 g
(Q + S) + (Q + R) + (R + S) = 280 + 350 + 330
2 Q + 2 R + 2 S = 960
2 x (Q + R + S) = 960
Q + R + S
= 960 ÷ 2
= 480 g
Average mass of the objects Q, R and S
= 480 ÷ 3
= 160 g
Answer(s): (a) 180 g; (b) 160 g