Sasi Math (Revised for 1024)

Scroll:Distance, Time and Speed >> Distance, Time & Speed >> ps (689)

Written Instructions:

For each Multiple Choice Question (MCQ), four options are given. One of them is the correct answer. Make your choice (1,2,3 or 4). Write your answers in the brackets provided..

For each Short Answer Question(SAQ) and Long Answer Question(LAQ), write your answers in the blanks provided.

Leave your answers in the simplest form or correct to two decimal places.

A motorist travelled $\frac{2}{5}$ of his journey at 50 $\frac{km}{h.}$ After which, he changed his speed to 60 $\frac{km}{h}$ and completed the rest of his journey in 2 $\frac{1}{2}$ hours. Given that the motorist reached his destination at 1.30 p.m., at what time did he start his journey

Answer:_______________

Mr Lim drove at 30 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 120 km at 60 $\frac{km}{h}$ . Calculate his average speed for the whole journey. Express your answer corrected to the nearest 2 decimal places.

$\frac{km}{h}$

Answer:_______________

A motorist travelled $\frac{2}{5}$ of his journey at 112 $\frac{km}{h.}$ After which, he changed his speed to 96 $\frac{km}{h}$ and completed the rest of his journey in 3 $\frac{1}{2}$ hours. Given that the motorist reached his destination at 1.30 p.m., at what time did he start his journey

Answer:_______________

Mr Lim drove at 60 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 480 km at 60 $\frac{km}{h}$ . Calculate his average speed for the whole journey. Express your answer corrected to the nearest 2 decimal places.

$\frac{km}{h}$

Answer:_______________

A motorist travelled $\frac{2}{5}$ of his journey at 65 $\frac{km}{h.}$ After which, he changed his speed to 78 $\frac{km}{h}$ and completed the rest of his journey in 2 $\frac{1}{2}$ hours. Given that the motorist reached his destination at 1.30 p.m., at what time did he start his journey

Answer:_______________

Mr Lim drove at 100 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 800 km at 80 $\frac{km}{h}$ . Calculate his average speed for the whole journey. Express your answer corrected to the nearest 2 decimal places.

$\frac{km}{h}$

Answer:_______________

A motorist travelled $\frac{2}{5}$ of his journey at 98 $\frac{km}{h.}$ After which, he changed his speed to 84 $\frac{km}{h}$ and completed the rest of his journey in 3 $\frac{1}{2}$ hours. Given that the motorist reached his destination at 1.30 p.m., at what time did he start his journey

Answer:_______________

Mr Lim drove at 45 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 360 km at 60 $\frac{km}{h}$ . Calculate his average speed for the whole journey. Express your answer corrected to the nearest 2 decimal places.

$\frac{km}{h}$

Answer:_______________

A motorist travelled $\frac{2}{5}$ of his journey at 55 $\frac{km}{h.}$ After which, he changed his speed to 66 $\frac{km}{h}$ and completed the rest of his journey in 2 $\frac{1}{2}$ hours. Given that the motorist reached his destination at 1.30 p.m., at what time did he start his journey

Answer:_______________

10)

Mr Lim drove at 75 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 300 km at 60 $\frac{km}{h}$ . Calculate his average speed for the whole journey. Express your answer corrected to the nearest 2 decimal places.

$\frac{km}{h}$

Answer:_______________

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	60 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 60 km
		=	150 km

Step 2: 1- $\frac{2}{5}$ = $\frac{3}{5}$

Step 3:	$\frac{3}{5}$ of the journey	→	150 km
	$\frac{1}{5}$ of the journey	ï»¿→	150 km ÷ 3
		=	50 km
	$\frac{2}{5}$ of the journey	→	2 x 50 km
		=	100 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	100 km ÷ 50 $\frac{km}{h}$
		=	2 h

Step 5:	Total travel time	→	2 $\frac{1}{2}$ h + 2 h
		=	4 $\frac{1}{2}$ h

Step 6:	Time the motorist started his journey	→	1.30 p.m. - 4 $\frac{1}{2}$ h
		=	9.00 a.m.

Answer: 50.00 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 120 km	→	120 km ÷ 60 $\frac{km}{h}$
		ï»¿=	2 h

Step 2: 1 - $\frac{1}{5}$ = $\frac{4}{5}$

Step 3:	$\frac{4}{5}$ of the journey	→	120 km
	$\frac{1}{5}$ of the journey	→	120 km ÷ 4
		=	30 km
	$\frac{5}{5}$ of the journey	→	5 x 30 km
		=	150 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	30 km ÷ 30 $\frac{km}{h}$
		=	1 h

Step 5:	Total time for the whole journey	→	2 h + 1 h
		=	3 h

Step 6:	Average speed	→	150 km ÷ 3 h
		=	50 $\frac{km}{h}$
		≈	50.00 $\frac{km}{h}$

Answer: 8.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	96 km
	3 $\frac{1}{2}$ h	ï»¿→	3 $\frac{1}{2}$ x 96 km
		=	336 km

Step 2: 1- $\frac{2}{5}$ = $\frac{3}{5}$

Step 3:	$\frac{3}{5}$ of the journey	→	336 km
	$\frac{1}{5}$ of the journey	ï»¿→	336 km ÷ 3
		=	112 km
	$\frac{2}{5}$ of the journey	→	2 x 112 km
		=	224 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	224 km ÷ 112 $\frac{km}{h}$
		=	2 h

Step 5:	Total travel time	→	3 $\frac{1}{2}$ h + 2 h
		=	5 $\frac{1}{2}$ h

Step 6:	Time the motorist started his journey	→	1.30 p.m. - 5 $\frac{1}{2}$ h
		=	8.00 a.m.

Answer: 60.00 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 480 km	→	480 km ÷ 60 $\frac{km}{h}$
		ï»¿=	8 h

Step 2: 1 - $\frac{1}{5}$ = $\frac{4}{5}$

Step 3:	$\frac{4}{5}$ of the journey	→	480 km
	$\frac{1}{5}$ of the journey	→	480 km ÷ 4
		=	120 km
	$\frac{5}{5}$ of the journey	→	5 x 120 km
		=	600 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	120 km ÷ 60 $\frac{km}{h}$
		=	2 h

Step 5:	Total time for the whole journey	→	8 h + 2 h
		=	10 h

Step 6:	Average speed	→	600 km ÷ 10 h
		=	60 $\frac{km}{h}$
		≈	60.00 $\frac{km}{h}$

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	78 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 78 km
		=	195 km

Step 2: 1- $\frac{2}{5}$ = $\frac{3}{5}$

Step 3:	$\frac{3}{5}$ of the journey	→	195 km
	$\frac{1}{5}$ of the journey	ï»¿→	195 km ÷ 3
		=	65 km
	$\frac{2}{5}$ of the journey	→	2 x 65 km
		=	130 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	130 km ÷ 65 $\frac{km}{h}$
		=	2 h

Step 5:	Total travel time	→	2 $\frac{1}{2}$ h + 2 h
		=	4 $\frac{1}{2}$ h

Step 6:	Time the motorist started his journey	→	1.30 p.m. - 4 $\frac{1}{2}$ h
		=	9.00 a.m.

Answer: 83.33 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 800 km	→	800 km ÷ 80 $\frac{km}{h}$
		ï»¿=	10 h

Step 2: 1 - $\frac{1}{5}$ = $\frac{4}{5}$

Step 3:	$\frac{4}{5}$ of the journey	→	800 km
	$\frac{1}{5}$ of the journey	→	800 km ÷ 4
		=	200 km
	$\frac{5}{5}$ of the journey	→	5 x 200 km
		=	1000 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	200 km ÷ 100 $\frac{km}{h}$
		=	2 h

Step 5:	Total time for the whole journey	→	10 h + 2 h
		=	12 h

Step 6:	Average speed	→	1000 km ÷ 12 h
		=	83.33333 $\frac{km}{h}$
		≈	83.33 $\frac{km}{h}$

Answer: 8.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	84 km
	3 $\frac{1}{2}$ h	ï»¿→	3 $\frac{1}{2}$ x 84 km
		=	294 km

Step 2: 1- $\frac{2}{5}$ = $\frac{3}{5}$

Step 3:	$\frac{3}{5}$ of the journey	→	294 km
	$\frac{1}{5}$ of the journey	ï»¿→	294 km ÷ 3
		=	98 km
	$\frac{2}{5}$ of the journey	→	2 x 98 km
		=	196 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	196 km ÷ 98 $\frac{km}{h}$
		=	2 h

Step 5:	Total travel time	→	3 $\frac{1}{2}$ h + 2 h
		=	5 $\frac{1}{2}$ h

Step 6:	Time the motorist started his journey	→	1.30 p.m. - 5 $\frac{1}{2}$ h
		=	8.00 a.m.

Answer: 56.25 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 360 km	→	360 km ÷ 60 $\frac{km}{h}$
		ï»¿=	6 h

Step 2: 1 - $\frac{1}{5}$ = $\frac{4}{5}$

Step 3:	$\frac{4}{5}$ of the journey	→	360 km
	$\frac{1}{5}$ of the journey	→	360 km ÷ 4
		=	90 km
	$\frac{5}{5}$ of the journey	→	5 x 90 km
		=	450 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	90 km ÷ 45 $\frac{km}{h}$
		=	2 h

Step 5:	Total time for the whole journey	→	6 h + 2 h
		=	8 h

Step 6:	Average speed	→	450 km ÷ 8 h
		=	56.25 $\frac{km}{h}$
		≈	56.25 $\frac{km}{h}$

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	66 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 66 km
		=	165 km

Step 2: 1- $\frac{2}{5}$ = $\frac{3}{5}$

Step 3:	$\frac{3}{5}$ of the journey	→	165 km
	$\frac{1}{5}$ of the journey	ï»¿→	165 km ÷ 3
		=	55 km
	$\frac{2}{5}$ of the journey	→	2 x 55 km
		=	110 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	110 km ÷ 55 $\frac{km}{h}$
		=	2 h

Step 5:	Total travel time	→	2 $\frac{1}{2}$ h + 2 h
		=	4 $\frac{1}{2}$ h

Step 6:	Time the motorist started his journey	→	1.30 p.m. - 4 $\frac{1}{2}$ h
		=	9.00 a.m.

10)

Answer: 62.50 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 300 km	→	300 km ÷ 60 $\frac{km}{h}$
		ï»¿=	5 h

Step 2: 1 - $\frac{1}{5}$ = $\frac{4}{5}$

Step 3:	$\frac{4}{5}$ of the journey	→	300 km
	$\frac{1}{5}$ of the journey	→	300 km ÷ 4
		=	75 km
	$\frac{5}{5}$ of the journey	→	5 x 75 km
		=	375 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	75 km ÷ 75 $\frac{km}{h}$
		=	1 h

Step 5:	Total time for the whole journey	→	5 h + 1 h
		=	6 h

Step 6:	Average speed	→	375 km ÷ 6 h
		=	62.5 $\frac{km}{h}$
		≈	62.50 $\frac{km}{h}$