Work Rate Practice Worksheet

Expressions · Equations · Quadratics — 5 Variations

Instructions: Show all your working clearly. For parts that say "show", you must derive the given result step by step to earn full marks (M1, A1).
Key Concept — Work Rate: If a person takes t minutes to complete one task, the number of tasks completed in T minutes is Tt. When two people work together, their combined rate equals the sum of individual rates.
VARIATION A

Packing Goodie Bags — Tomo & Benjamin

[5 marks]
Question 1

Tomo and Benjamin are helping the school to pack goodie bags for the students.

(a) Tomo takes y minutes to pack a goodie bag. Write down an expression in terms of y, for the number of goodie bags Tomo can pack in an hour.

Answer ______________________ [1]


(b) Benjamin takes 1 minute longer than Tomo to pack a goodie bag. Write down an expression in terms of y, for the number of goodie bags Benjamin can pack in an hour.

Answer ______________________ [1]


(c) Tomo and Benjamin together can pack a total of 64 goodie bags in an hour. Form an equation in y and show that it reduces to

16y2 − 14y − 15 = 0

[3]


(d) Solve the equation 16y2 − 14y − 15 = 0.

Answer y = _______ or _______ [2]


(e) How many goodie bags can Tomo pack in 3 hours?

Answer ______________________ [1]

VARIATION B

Making Sandwiches — Alice & Ben

[5 marks]
Question 2

Alice and Ben are preparing sandwiches for a school event.

(a) Alice takes x minutes to make one sandwich. Write down an expression in terms of x, for the number of sandwiches Alice can make in an hour.

Answer ______________________ [1]


(b) Ben takes 2 minutes longer than Alice to make one sandwich. Write down an expression in terms of x, for the number of sandwiches Ben can make in an hour.

Answer ______________________ [1]


(c) Alice and Ben together can make a total of 32 sandwiches in an hour. Form an equation in x and show that it reduces to

4x2 − 7x − 15 = 0

[3]


(d) Solve the equation 4x2 − 7x − 15 = 0.

Answer x = _______ or _______ [2]


(e) How many sandwiches can Alice make in 1 hour?

Answer ______________________ [1]

VARIATION C

Folding Boxes — Mei Ling & Wei Jie

[5 marks]
Question 3

Mei Ling and Wei Jie are folding cardboard boxes for a charity drive.

(a) Mei Ling takes t minutes to fold one box. Write down an expression in terms of t, for the number of boxes Mei Ling can fold in an hour.

Answer ______________________ [1]


(b) Wei Jie takes 1 minute longer than Mei Ling to fold one box. Write down an expression in terms of t, for the number of boxes Wei Jie can fold in an hour.

Answer ______________________ [1]


(c) Mei Ling and Wei Jie together can fold a total of 27 boxes in an hour. Form an equation in t and show that it reduces to

9t2 − 31t − 20 = 0

[3]


(d) Solve the equation 9t2 − 31t − 20 = 0.

Answer t = _______ or _______ [2]


(e) How many boxes can Mei Ling fold in 3 hours?

Answer ______________________ [1]

VARIATION D

Wrapping Gifts — Sarah & Tom

[5 marks]
Question 4

Sarah and Tom are wrapping gifts for a school charity event.

(a) Sarah takes m minutes to wrap one gift. Write down an expression in terms of m, for the number of gifts Sarah can wrap in an hour.

Answer ______________________ [1]


(b) Tom takes 4 minutes longer than Sarah to wrap one gift. Write down an expression in terms of m, for the number of gifts Tom can wrap in an hour.

Answer ______________________ [1]


(c) Sarah and Tom together can wrap a total of 40 gifts in an hour. Form an equation in m and show that it reduces to

m2 + m − 6 = 0

[3]


(d) Solve the equation m2 + m − 6 = 0.

Answer m = _______ or _______ [2]


(e) How many gifts can Sarah wrap in 3 hours?

Answer ______________________ [1]

VARIATION E

Making Paper Cranes — Lily & Grace

[5 marks]
Question 5

Lily and Grace are making paper cranes for a school art exhibition.

(a) Lily takes k minutes to make one paper crane. Write down an expression in terms of k, for the number of paper cranes Lily can make in an hour.

Answer ______________________ [1]


(b) Grace takes 1 minute longer than Lily to make one paper crane. Write down an expression in terms of k, for the number of paper cranes Grace can make in an hour.

Answer ______________________ [1]


(c) Lily and Grace together can make a total of 22 paper cranes in an hour. Form an equation in k and show that it reduces to

11k2 − 49k − 30 = 0

[3]


(d) Solve the equation 11k2 − 49k − 30 = 0.

Answer k = _______ or _______ [2]


(e) How many paper cranes can Lily make in 1.5 hours?

Answer ______________________ [1]