Please help me with my algebra homework. will award to the first person to answer correctly and w/ explanation

Question

Calvin earns $400 working at the market to help pay his share of a trip with Phoebe's family. To supplement his earnings, Calvin's mother will give him an additional 20% of what he earns,, and his father will give him an additional 30% of what he earns. -----------A) how much will he get from each parent?--------B) Calvins asks if his mother will give him 20% of the TOTAL he gets from working and from his father. He also asks if his father will give 30% of the total he gets from working and from his mother. His parents agree, provided Calvin can figure out the right amounts. How much will Calvin get from each parent under these conditions? -----------C) How much more will Calvin get in part B than in part A?

Answer 1

A)
$400*.2 = $80 from Mom
$400*.3 = $120 from Dad

B) You can't just plug 80 and 120 into this question, because he'll get more from his Mom, which will make his Dad give him more, which will make his Mom give him more, which will make his Dad give him more, etc.

His Mom will give him 20% of the total of his earnings plus what he gets from his Dad, so the equation is:
M = .2(400 +D)

Same with Dad, only it's 30%:
D = .3(400 +M)

substitute for D and solve for M
M = .2(400 +.3(400+M))
M = 80 + .2(120 + .3M) = 80 +24 + .06M
.96M= 104
M = $108.33

Now, put that number into the equation and solve for D
D = .3(400+108.33) = $169.44

C) $108.33 + $169.44 - $(80+200) = $77.77

Answer 2

10% of $400 = $40 (divide by 100 and multiply by 10)

20% of $400 = $80 so this is mom's contribution
30% of $400 = $120 so this is dad's contribution


b) this keeps changing as each parents contribution increases due to the others increasing.

if 20% of $400 + $120 is Mom's new contribution it will be 20% of $520 (10% = $52) = $104

if 30% of $400 + $80 is dad's new contribution it will be 20% of $480 (10% = $48) = $144

c) the total from both parents in (a) is $80+$120=$200
the total from both parents in (b) is $104+$144=$248

$248-$200=$48 so (b) provides at least $48 more than (a)

Answer 3

A. Mother will give him 20% of $400.
$400 x .20 = $80.00

Father will give him 30% of $400.
$400 x .30 = $120.00

B. The total Calvin will get from his father is $400 + $120 = $520. Therefore Calvin's mother will give him 20% of $520.
$520 x .20 = $104.00

The total Calvin will get from his mother is $400 + $80 = $480. Therefore Calvin's father will give him 30% of $480.
$480 x .30 = $144.00

C. The total amount Calvin will get from his parents in part B is $248. The total amount he will get from h is parents in part A is $224.00

Answer 4

A:

20% from mom $80
30% from dad $120

B:
$104 if mom matches 20% of $520
$144 if dad matches 30% of $480

C: $848