## Saturday, November 6, 2010

### Percentage P6

If Larry sells his toy at a discount of 20%, he can still make a gain of \$150. If he sells it at a 45% discount, he will lose \$325. How much did Larry pay for his toy?

80%  -->  1 u  +  \$150

55%  -->  1 u  -  \$325

80%  -  55%  -->  150  -  (- 325)

25%  -->  150  +  325  =  \$475

80%  -->  80/25  x  475  =   \$1520

1520 -  150  =  \$1370

It was \$1370.

### Ratio P6

Larry, May and Nora shared the cost of a meal. The ratio of the amount paid by Larry to the total amount paid by May and Nora is 2 : 3 while May’s share was 20% of the total amount paid by Larry and Nora. Given that Nora paid \$84 more than May, how much did the meal cost?

L : M + N  =  2  :  3
=  12  :  18  [x 6 to get total of same total of 30]

M : L + N  =  20  :  100
=  1  :  5
=  5  :  25   [x 5 to get same total of 30]

30 - 12 - 5 = 13

L : M : N = 12  :  5  :  13

13 - 5 = 8

8 u  -->  \$84

30 u  -->  30/8  x  84  =  \$315

It was \$315.

### Ratio P6

Ali, Bill and Cindy had a total of 450 apples. The ratio of the number of apples Bill had to the number of apples that Cindy had was 2 : 5. After Ali and Bill had given away ½ of their apples, the children had 300 apples left. How many apples did Bill have at first?

A [  ][  ]                  ]
B [][][][]                 ]  450
C [][][][][][][][][][]  ]

A [  ]                      ]
B [][]                      ]  300
C [][][][][][][][][][]  ]

300 x 2 = 600
10 u --> 600 - 450 = 150

4 u  -->  4/10  x 150  =  60 apples

Bill had  60 apples  at first.