Last week, Jamie counted the number of rice grains in his plate, and found he had 250 grains.
He had rice this week, and counted only 175 grains.
Find the percentage decrease.

1) questions completed in first week=140

  questions completed in second week=182

 increased number=182-140=42

 percentage increase=increase number / original number x 100%

                                    =>(42/140) x 100%

                                    =>(3/10) x 100%

                                    3 x 10=30%

therefore increase percent =30%

2) grains found in first week=250

  grains found in second week=175

                difference in grains= 250-175=75

                  decrease percent =(decrease/original no.) x 100%

                                                =(75/250) x 100%

                                                =(3/10) x 100%

                                                =3 x 10%

                                               =30%

therefore the decrease percent= 30%

3) original mass of the chocolate bar= 340gms

   increased by =  15%

   new mass=340 + 15%

    first lets find out 15 % of 340

 =340 x 15%

=340 x 15/100

=  34 x 1.5

= 51

now, lets add 340 and 51 to get new value

   =340+51=391

therefore the new mass of chocolate is 391 grams

Step-by-step explanation: