How many times will the digit '3' appear if we write b all whole numbers from 1 to 999?

280

Step-by-step explanation:

100 times in the hundreds place: {300,301,3021,303,304, …,399}

90 times in the tens place: {130–139, 230–239, 330–339, …, 930–939}

90 times in the ones place: {103,113,123,…,193, 203,213,…293, 303,…393, . . . , 903,…,993}

its 300, because if you count yull get that and its right

Step-by-step explanation:

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."