wells.
MPC - marginal propencity to consume
MPS - marginal propencity to save
its like the likelyhood to consume/save. You noe that mps + mpc = 1
eg; if mpc = 0.8, mps = 0.2
so, to find the multiplier, you use the formula dats given to u in the text book;
multiplier = 1/mps, or 1/1-mpc (since mps + mpc = 1)
in this case ( mpc = 08, mps = 0.2 )
k = 1/0.2 = k
therefore, the multiplier is k = 5
from here you just times the multiplier with the given amount in the question... to get the multiplier effect