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 80 $\frac{km}{h.}$ After which, he changed his speed to 96 $\frac{km}{h}$ 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 480 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 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 40 $\frac{km}{h}$ 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 77 $\frac{km}{h.}$ After which, he changed his speed to 66 $\frac{km}{h}$ 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 100 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 400 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 75 $\frac{km}{h.}$ After which, he changed his speed to 90 $\frac{km}{h}$ 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 50 $\frac{km}{h}$ for $\frac{1}{5}$ of the journey and drove the remaining 200 km at 100 $\frac{km}{h}$ . 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 95 $\frac{km}{h.}$ After which, he changed his speed to 114 $\frac{km}{h}$ 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 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:_______________

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	96 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 96 km
		=	240 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	240 km
	$\frac{1}{5}$ of the journey	ï»¿→	240 km ÷ 3
		=	80 km
	$\frac{2}{5}$ of the journey	→	2 x 80 km
		=	160 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	160 km ÷ 80 $\frac{km}{h}$
		=	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 480 km	→	480 km ÷ 80 $\frac{km}{h}$
		ï»¿=	6 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	→	6 h + 2 h
		=	8 h

Step 6:	Average speed	→	600 km ÷ 8 h
		=	75 $\frac{km}{h}$
		≈	75.00 $\frac{km}{h}$

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: 66.67 $\frac{km}{h}$

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 ÷ 40 $\frac{km}{h}$
		=	2 h

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

Step 6:	Average speed	→	400 km ÷ 6 h
		=	66.66667 $\frac{km}{h}$
		≈	66.67 $\frac{km}{h}$

Answer: 8.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	66 km
	3 $\frac{1}{2}$ h	ï»¿→	3 $\frac{1}{2}$ x 66 km
		=	231 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	231 km
	$\frac{1}{5}$ of the journey	ï»¿→	231 km ÷ 3
		=	77 km
	$\frac{2}{5}$ of the journey	→	2 x 77 km
		=	154 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	154 km ÷ 77 $\frac{km}{h}$
		=	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: 83.33 $\frac{km}{h}$

SOLUTION 1 :

Step 1:	Time to cover the last 400 km	→	400 km ÷ 80 $\frac{km}{h}$
		ï»¿=	5 h

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

Step 3:	$\frac{4}{5}$ of the journey	→	400 km
	$\frac{1}{5}$ of the journey	→	400 km ÷ 4
		=	100 km
	$\frac{5}{5}$ of the journey	→	5 x 100 km
		=	500 km

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

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

Step 6:	Average speed	→	500 km ÷ 6 h
		=	83.33333 $\frac{km}{h}$
		≈	83.33 $\frac{km}{h}$

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	90 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 90 km
		=	225 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	225 km
	$\frac{1}{5}$ of the journey	ï»¿→	225 km ÷ 3
		=	75 km
	$\frac{2}{5}$ of the journey	→	2 x 75 km
		=	150 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	150 km ÷ 75 $\frac{km}{h}$
		=	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 200 km	→	200 km ÷ 100 $\frac{km}{h}$
		ï»¿=	2 h

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

Step 3:	$\frac{4}{5}$ of the journey	→	200 km
	$\frac{1}{5}$ of the journey	→	200 km ÷ 4
		=	50 km
	$\frac{5}{5}$ of the journey	→	5 x 50 km
		=	250 km

Step 4:	Time to cover the first $\frac{1}{5}$ of the journey	→	50 km ÷ 50 $\frac{km}{h}$
		=	1 h

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

Step 6:	Average speed	→	250 km ÷ 3 h
		=	83.33333 $\frac{km}{h}$
		≈	83.33 $\frac{km}{h}$

Answer: 9.00 a.m.

SOLUTION 1 :

Step 1:	1h	→	114 km
	2 $\frac{1}{2}$ h	ï»¿→	2 $\frac{1}{2}$ x 114 km
		=	285 km

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

Step 3:	$\frac{3}{5}$ of the journey	→	285 km
	$\frac{1}{5}$ of the journey	ï»¿→	285 km ÷ 3
		=	95 km
	$\frac{2}{5}$ of the journey	→	2 x 95 km
		=	190 km

Step 4:	Time taken to complete the first $\frac{2}{5}$ of the journey	→	190 km ÷ 95 $\frac{km}{h}$
		=	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: 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 $\frac{km}{h}$