Fraction Puzzles MR Flashcards
Mrs Cook bakes a cake. She cuts it into 8 pieces. If she sells 3/4 of the cake at the cake sale, how many pieces are left?
3/4 = 6/8. Therefore 6 pieces sold, and 2 left over
Adam & his friends are going for a mountain bike ride. The route is 30km, but they only ride 1/3 of that distance in total. If 1/2 of their route was flat, how many km of flat did they ride?
5km
Matt wins a trip to watch Man United play against Chelsea. He can take 3 friends with him, but they have to pay 1/2 of their plane ticket, 1/4 of the hotel bill and 1/3 of the ticket for the game. The plane ticket costs R8000, the hotel will cost R2000 and the ticket for the game will cost R900. Matt asks Adam, Jo and Finn if they would like to come. Matt has R300 pocket money to help one of his friends if needed.
Jo has R4500
Finn has R4800
Adam has R5000.
Who can go with Matt (assuming their parents say “Yes!”)
They need r4800 each.
If Matt gives Jo his R300, then Jo will have R4800, and they can all go with.
Karen is in the play. In the first scene, there are 200 lines, and she has to learn 2/8 of them. In the second scene, there are 150 lines, and she las to learn 1/3 of them. How many lines does she have to learn all together?
2/8 of 200 = 50
1\3 of 150 = 50
Karen has to learn 100 lines in total
Finn & his friends go for another ride at Meerendal. The route they do is 20km, and 1/4 of the route is uphill. How many km of uphill did they ride? They ride the same amount downhill. If they ride 5 km/hr uphill, 10 km/hr on the flat, & 20km/hr downhill, how long did the ride take them?
5km of uphill, & 5km of downhill. Therefore 10km of flat.
Time for each section:
Uphill: 5km/hr means that 5km will take them 1hr (60min)
Downhill: 20km/hr. 5 is 1/4 of 20, so 5km downhill will take them 1/4 of an hour, or 15 min
Flat: 10km/hr means that 10km will take them 1 hour (60min)
Total time = 60 + 15 + 60 = 135min, or 2h15m.
Emma’s mum is making chocolate brownies for her birthday. She makes 30 brownies in total. Rebecca asks if she can have 1 brownie each for her and two friends. What fraction of the brownies does Emma have left to take to school?
Rebecca and 2 friends take 3 brownies.
3 out of 30 = 1/10. Therefore Emma has 9/10 of the brownies left
The awesome Mrs Redfern bakes 48 pieces of millionaire shortbread for the cake sale. At first break, she sold 1/2 of the pieces at R5 each. At 2nd break she sold a further 2\3 of the remaining pieces at R3 each. How much money did she make all together?
Bonus question: who do you think ate the leftovers?
1/2 of 48 = 24 pieces at R5 each. 5 x 24 = R120
2\3 of 24 = 16 pieces at R3 each. 3 x 16 = R48
Total = R120 + R48 = R168
Bonus q: Nick and his brothers of course! - and none left for dad :(
The senior choir has won the ATKV choir competition! They are going to PE for the national event. It costs R50000 for the whole choir to go to PE. The choir organises an Amazing Goose Race, and raise 1/2 the money they need. They then do face painting at Howard Centre on a Saturday morning and raise 1/4 of the total. Finally, they sing for a morning at the Kirstenbosch craft market and raise another 1/8 of the total.
If there are 50 children in the choir, how much money do they still need to each contribute?
2 (or more) approaches to solving this puzzle.
Option 1: add up the individual amounts they made.
Goose race: 1/2 of R50000 = R25000
Face painting: 1/4 of R50000 = R12500
Singing: 1/8 of R50000 = R6250
Total raised = R25000 + R12500 + R6250 = R43750
Total remaining = R50000 - R43750 = r6250
Each child must contribute: R6250 divided by 50 = R125
Option 2: create the amount raised into one fraction
Choose the smallest fraction. In this case, it is 1/8. You must then convert the other two fractions into eighths.
1/2 = 4/8
1/4 = 2/8
Total raised = 4/8 + 2/8 + 1/8 = 7/8. They raised 7/8 of the money they needed.
7/8 of R50000 = 7 x R50000 divided by 8 = R43750.
It’s fiercely competitive in the Redfern household in 2016, about whose class can collect the most newspapers. Sam’s class collects 80 bags. Zach’s class collects 1/4 of Sam’s class. Matt’s class collects 3/5 of Sam’s class. How many bags did Zach and Matt’s class each collect?
Zach: 20
Matt: 48
Jo and Adam want to buy chips at the tuck shop. Jo has R20, but only wants to spend 1/4 of his pocket money. Adam has R24, but only wants to spend 3/4 of his pocket money. The packet of chips cost R4 each. How many packets of chips can they buy together?
Jo can spend R5
Adam can spend R18
Together they have R23.
They can buy 5 packets of chips (5 x R4 = R20) and they will have R3 left over.
