Reasoning · Grade 3-2 Interpreting Graphs
Problem
A never reaches 0 and B beats C, so (1) is right.
The bus that touches the bottom line (0 m left) soonest is the one that gets there first; A's flat line never touches 0.
3.MD.B.3Draw A DiagramC has three flat stretches, so (2) is right.
Each level 'step' on the staircase is a pause where the distance stays the same — count the steps to count the stops.
3.MD.B.3Draw A DiagramB is a straight line at constant speed, so (3) is wrong.
A ruler-straight drop means the bus covers equal distance each second — steady, not faster and faster.
3.MD.B.3Eliminate PossibilitiesA ruler-straight drop means the bus covers the same distance each second, so it is steady rather than speeding up.
Equal drops in equal times is exactly a fixed step repeated, and a speeding-up bus would take bigger and bigger steps instead.
With a steady speed the distance covered keeps a fixed ratio to the time, so twice the time really is twice the distance.
A flattens above 0, so it is stopped — (4) is right.
If the 'distance left' never goes down, the bus is sitting still — exactly what a breakdown partway would look like.
3.MD.B.3Draw A DiagramB and C start level and both reach 0, so (5) is wrong.
Both buses go from the same starting distance down to the stop, so they cover the same ground — C just dawdled with stops.
3.MD.B.3Eliminate PossibilitiesOn a 'distance-left' graph, flat means stopped and a straight fall means steady speed — that's all you need to spot the wrong claims!