Fractions: WJEC GCSE Foundation November 2019 Unit 2 Q15

Foundation November 2019 Unit 2 Q15

WJECFoundationCurrent spec5 marksFractions Units & Time

15. A task takes 6 hours 15 minutes to complete.

\(\dfrac{2}{5}\) of this time is spent on planning.

How long was spent on the rest of the task?
Give your answer in hours and minutes.

You must show all your working. [5]

Mark scheme

Scheme	Marks	Comments
Sight of 6·25 (hrs) OR 375 (min)	B1
(Planning =) \(\dfrac{2}{5}\) × 6·25 OR \(\dfrac{2}{5}\) × 375	M1	F.T. ‘their time’ in hours or in minutes. May be seen in parts (1/5^th and then 2/5ths)
= 2·5 (hrs) OR 150 (min)	A1	[Note: 2/5 × 6·15 OR 2/5 × 615 is B0M1(FT) = 2·46(hrs) OR 246(min) A1(FT) BUT A0 if 2·46 then used as 2h 46m ]
(Remainder of work = 6·25 − 2·5 OR 375 – 150 =) 3·75 (hrs) OR 225 (min)	B1	F.T. ‘their derived times’ using same units.
= 3 hours 45 minutes	B1	F.T. correct conversion of ‘their times’, correct to the nearest minute (rounded or truncated), if of equivalent difficulty. Allow unambiguous indication of units.

Scheme	Marks	Comments
Sight of 6·25 (hrs) OR 375 (min)	B1
(Remaining work takes) 3/5 of time	B1
= 3/5 × 6·25 OR 3/5 × 375	M1	F.T. ‘their time’ in hours or in minutes.
= 3·75 (hrs) OR 225 (min)	A1
= 3 hours 45 minutes	B1	F.T. correct conversion of ‘their times’, correct to the nearest minute (rounded or truncated), if of equivalent difficulty. Allow unambiguous indication of units.

Scheme	Marks	Comments
(Planning =) \(\dfrac{2}{5}\) × 6 AND \(\dfrac{2}{5}\) × 15	M1
= 2·4(hrs) AND 6(min)	A1	2·4 hrs may be given as 2hrs 24min.
= 2hrs 30min	A1	C.A.O.
(Remainder of work =) 6(hr) 15(min)−2(hrs) 30(min)	M1	F.T. ‘their derived planning time’ in hours and min.
= 3 hours 45 minutes	A1

Scheme	Marks	Comments
(Remaining work takes) 3/5 of time	B1
= \(\dfrac{3}{5}\) × 6 AND \(\dfrac{3}{5}\) × 15	M1
= 3·6(hrs) AND 9(min)	A1	3·6 hrs may be given as 3hrs 36min.
= 3hrs 36min + 9(min)	M1	F.T. ‘their derived times’ in hours and min.
= 3 hours 45 minutes	A1