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
= 490 - 180
= 310 g
Mass of Q and R
= 440 - 180
= 260 g
Mass of R and S
= 510 - 180
= 330 g
(Q + S) + (Q + R) + (R + S) = 310 + 260 + 330
2 Q + 2 R + 2 S = 900
2 x (Q + R + S) = 900
Q + R + S
= 900 ÷ 2
= 450 g
Average mass of the objects Q, R and S
= 450 ÷ 3
= 150 g
Answer(s): (a) 180 g; (b) 150 g