Answer:
$153.75
Step-by-step explanation:
$71.75 / 7=$10.25
$10.25 x 15 =$153.75
Normal income: 25 $
Last week's income: 25 + 20: 45 $
% = Last week's/normal = 45/25 ×100 =180 %
Sometimes it helps to draw it out...
(17)
C_______M_________Q
|___________________|
21
therefore, CM + MQ = CQ
17 + MQ = 21
MQ = 21 - 17
MQ = 4 <===