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 60 $\frac{km}{h.}$ After which, he changed his speed to 72 $\frac{km}{h}$ 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 240 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 100 $\frac{km}{h.}$ After which, he changed his speed to 120 $\frac{km}{h}$ 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 45 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 180 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:_______________

Mr Lim drove at 60 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 240 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 133 $\frac{km}{h.}$ After which, he changed his speed to 114 $\frac{km}{h}$ 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 80 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 320 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 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:_______________

10)

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:_______________

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	72 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 72 km
		=	180 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	180 km
	$\frac{1}{5}$ of the journey	ï»¿→	180 km ÷ 3
		=	60 km
	$\frac{2}{5}$ of the journey	→	2 x 60 km
		=	120 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	120 km ÷ 60 $\frac{km}{h}$
		=	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 240 km	→	240 km ÷ 60 $\frac{km}{h}$
		ï»¿=	4 h

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

Step 3:	$\frac{4}{5}$ of the journey	→	240 km
	$\frac{1}{5}$ of the journey	→	240 km ÷ 4
		=	60 km
	$\frac{5}{5}$ of the journey	→	5 x 60 km
		=	300 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	60 km ÷ 30 $\frac{km}{h}$
		=	2 h

Step 5:	Total time for the whole journey	→	4 h + 2 h
		=	6 h

Step 6:	Average speed	→	300 km ÷ 6 h
		=	50 $\frac{km}{h}$
		≈	50.00 $\frac{km}{h}$

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	120 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 120 km
		=	300 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	300 km
	$\frac{1}{5}$ of the journey	ï»¿→	300 km ÷ 3
		=	100 km
	$\frac{2}{5}$ of the journey	→	2 x 100 km
		=	200 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	200 km ÷ 100 $\frac{km}{h}$
		=	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: 56.25 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 180 km	→	180 km ÷ 60 $\frac{km}{h}$
		ï»¿=	3 h

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

Step 3:	$\frac{4}{5}$ of the journey	→	180 km
	$\frac{1}{5}$ of the journey	→	180 km ÷ 4
		=	45 km
	$\frac{5}{5}$ of the journey	→	5 x 45 km
		=	225 km

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

Step 5:	Total time for the whole journey	→	3 h + 1 h
		=	4 h

Step 6:	Average speed	→	225 km ÷ 4 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.

Answer: 75.00 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 240 km	→	240 km ÷ 80 $\frac{km}{h}$
		ï»¿=	3 h

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

Step 3:	$\frac{4}{5}$ of the journey	→	240 km
	$\frac{1}{5}$ of the journey	→	240 km ÷ 4
		=	60 km
	$\frac{5}{5}$ of the journey	→	5 x 60 km
		=	300 km

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

Step 5:	Total time for the whole journey	→	3 h + 1 h
		=	4 h

Step 6:	Average speed	→	300 km ÷ 4 h
		=	75 $\frac{km}{h}$
		≈	75.00 $\frac{km}{h}$

Answer: 8.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	114 km
	3 $\frac{1}{2}$ h	ï»¿→	3 $\frac{1}{2}$ x 114 km
		=	399 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	399 km
	$\frac{1}{5}$ of the journey	ï»¿→	399 km ÷ 3
		=	133 km
	$\frac{2}{5}$ of the journey	→	2 x 133 km
		=	266 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	266 km ÷ 133 $\frac{km}{h}$
		=	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: 80.00 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 320 km	→	320 km ÷ 80 $\frac{km}{h}$
		ï»¿=	4 h

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

Step 3:	$\frac{4}{5}$ of the journey	→	320 km
	$\frac{1}{5}$ of the journey	→	320 km ÷ 4
		=	80 km
	$\frac{5}{5}$ of the journey	→	5 x 80 km
		=	400 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	80 km ÷ 80 $\frac{km}{h}$
		=	1 h

Step 5:	Total time for the whole journey	→	4 h + 1 h
		=	5 h

Step 6:	Average speed	→	400 km ÷ 5 h
		=	80 $\frac{km}{h}$
		≈	80.00 $\frac{km}{h}$

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.

10)

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 $\frac{km}{h}$