Samuel left his house at t = 0 mins
He drove to the store 10 blocks away at a speed of 2 blocks per minute.
After the first two minutes, the number of blocks passed was:
n = 2 blocks per miunte * 2 = 4 blocks
Speed is given as distance per time, therefore:
2 blocks per minute = 10 blocks / t
t = 10 / 2 = 5 minutes
It took Samuel 5 minutes.
He stopped and went into the shop for 7 minutes. This means that 12 minutes have elapsed altogether.
He drove in the same direction at a speed of 1 block per minute until he got to the bank 2 blocks away. He is now 12 blocks away from home. This means that:
1 bpm = 2 / t
t = 2 minutes
Therefore, 14 minutes have elapsed in total.
He stopped at the bank for 3 minutes. 17 minutes have elapsed in total.
Then, he drove home at a speed of 2 blocks per minute.
He passed a total of 12 blocks. Therefore, the time it took him to get home is:
2 bpm = 12 blocks / t
t = 12 / 2 = 6 minutes
Therefore, a total of 23 minutes have passed.
We have that:
Time (minutes) 2 5 12 14 17 23
Number of blocks 4 10 10 12 12 0
The attached image is the plotted graph:
The shape of the graph takes a quadratic form