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Practice: percent change

Practice: percent change

1

Work out the amount after the change.

a
350 ₪, a 12% rise

    / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

    / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

    b
    80 ₪, a 15% discount

      / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

      / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

      c
      2500 ₪, an 18% rise (VAT)

        / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

        / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

        2

        Solve.

        a
          b
            c
              3

              The number of visitors to the town library rose from 1250 in the month before its renovation to 1500 in the month after.
              By what percent did the number of visitors rise?

                / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

                / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

                4

                After a 35% discount, a game costs 117 ₪.
                How much did the game cost before the discount?

                5

                The price of a product rose by 20%, and then fell by 20%.
                By what percent did the price change altogether?
                Did it rise or fall?

                  / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

                  / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

                  6

                  At the start of the summer a pool held 4000 litres of water.
                  Every week 5% of the water in it evaporated.
                  How many litres of water were left in the pool after two weeks?

                    / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

                    / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

                    7

                    At a school, 40% of the students walk, 35% come by bicycle, and the rest – 120 students – come by bus.
                    How many students are in the school?

                      / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power

                      / – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power

                      8

                      The price of a book fell from 80 ₪ to 60 ₪.
                      Yael says: “The price fell by 25%.”
                      Amit says: “The price fell by 3313%\displaystyle 33\frac{1}{3}\%.”
                      Who is right?
                      What was the other one’s mistake?