document.write( "Question 1199553: Once a month, Benfort put some money into the bamboo jar. Each month, he put 50 centavos more into the jar than the month before. On its 12th yr, he counted his money for his graduation; and he had Php 5, 436. How much money did he put in the jar in the last month? \n" ); document.write( "

Algebra.Com's Answer #833486 by greenestamps(13200) $\"\"$ $\"About$

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\n" ); document.write( "Once a month for 12 years means 12*12 = 144 deposits.

\n" ); document.write( "The final amount was 5436; the average deposit was 5436/144 = 37.75.

\n" ); document.write( "The average deposit is the average of the first and last deposits:
\n" ); document.write( "(first + last)/2 = 37.75
\n" ); document.write( "first + last = 2*37.75 = 75.5 [1]

\n" ); document.write( "The last deposit is the first deposit, plus the common difference of 50c = 0.5p 119 times:
\n" ); document.write( "last = first + 119(0.5) = first + 59.5 [2]

\n" ); document.write( "From [1] and [2]...
\n" ); document.write( "first + last = first + first + 59.5 = 75.5
\n" ); document.write( "2*first = 16
\n" ); document.write( "first = 8 [3]

\n" ); document.write( "From [2] and [3], last = 8 + 59.5 = 67.5

\n" ); document.write( "ANSWER: He put Php 67.5 in the jar the last month

\n" ); document.write( "CHECK: $\"144%28%288%2B67.5%29%2F2%29=144%2A37.75=5436\"$

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