Question 1164217
There are 1580 adults and children on a ship. 60% of them are adults.when the ship stops at the harbour, some of the adults alight and the percentage of the adults remaining on the ship decreases to 20%. How many adults alight from the ship......??
<pre>With 60% of the 1,580 individuals on board being adults, we get .6(1,580) = 948 adults

Let number of adults that alit be A
Then the number of adults that remained = 948 - A, and the remaining individuals on board = 1,580 - A
We then get: {{{matrix(1,3, (948  -  A)/("1,580"  -  A), "=", .2)}}}
          .2(1,580 - A) = 948 - A ------- Cross-multiplying
              316 - .2A = 948 - A
              - .2A + A = 948 - 316
                    .8A = 632
Number of adults that alit, or {{{highlight_green(matrix(1,5, A, "=", 632/.8, "=", 790))}}}