Having trouble with a couple problems:
A student scores 93,89,72,80 and 96 on the first 5 tests. What did she score on test 6 if her average is 83?
Better buy Appliances marks up its wholesale prices by 30% to determine retail prices. If a dishwasher retails for $599, what was the whole sale price of this item?
Find 5 consecutive integers such that their sum is 140.
Thanks
2007-08-30 17:21:23 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
If her average over 6 tests is 83, her total over 6 tests is 83×6 = 498. Her total on the first five tests is 430, so she must have scored 68 on the sixth test.
retail price = wholesale price × (1 + 30/100)
so if the wholesale price is $x, we have
599 = x × 1.3
So x = 599/1.3 = $461 to the nearest dollar.
average = 140/5 = 28, this will be the number in the middle.
So the numbers are 26, 27, 28, 29, 30.
2007-08-30 17:28:46 · answer #1 · answered by Scarlet Manuka 7 · 0⤊ 0⤋
3rd question:
5 consecutive integers: to find them divide 140 by 5 = 28
Make 28 as the middle number, that will give you the following numbers:
26 + 27 + 28 + 29 + 30 = 140
2nd question:
599 * 30% = 179.7
Wholesale = 599 - 179.7 = 419.3
1st question:
Test 6 = 68
93 +89 + 72 + 80 + 96 + 68 = 498
498 / 6 = 83
2007-08-30 17:32:15 · answer #2 · answered by Emitz 2 · 0⤊ 0⤋
To solve #1) use the equation 93+89+72+80+96+x divided by 6 = 83 and solve for x
To solve #3) the equation would be x+ (x+1) + (x+2) + (x+3) + (x+4) = 140
2007-08-30 17:30:17 · answer #3 · answered by KLM 1 · 0⤊ 0⤋
(93+89+72+80+96+a)/6=83
(93+89+72+80+96+a)=83 x 6
(93+89+72+80+96+x)=498
430+x=498
x=498-430
x=68
599-(0.30x599)=a
599-179.7=a
419.3=a
x+(x+1)+(x+2)+(x+3)+(x+4)=140
5x+10=140
5x=130
x=26
26, 27, 28, 29, 30
2007-08-30 17:30:35 · answer #4 · answered by Jennifer P 1 · 0⤊ 0⤋