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 = 200 g
(b)
Mass of Q and S
= 480 - 200
= 280 g
Mass of Q and R
= 520 - 200
= 320 g
Mass of R and S
= 440 - 200
= 240 g
(Q + S) + (Q + R) + (R + S) = 280 + 320 + 240
2 Q + 2 R + 2 S = 840
2 x (Q + R + S) = 840
Q + R + S
= 840 ÷ 2
= 420 g
Average mass of the objects Q, R and S
= 420 ÷ 3
= 140 g
Answer(s): (a) 200 g; (b) 140 g