Answer:
Marginal Propensity to save=0.6
Step-by-step explanation:
In order to calculate Marginal Propensity of save, we have to find the marginal Propensity to consume.
Marginal Propensity to consume=Consumption Change/Income change
Marginal Propensity to consume=

Change in Consumption=$40,000-$38,000
Change in Consumption=$2000
Change in income=$55,000-$50,000
Change in income=$5,000
Marginal Propensity to consume=

Marginal Propensity to consume= 0.4
Now,
Marginal Propensity to consume + Marginal Propensity to save=1
0.4 + Marginal Propensity of save=1
Marginal Propensity of save=1-0.4
Marginal Propensity to save=0.6