This graph shows how a radio-active substance loses its radioactivity over time. The half life of the substance is how long it takes to decay to half of its original mass. What is the half life of this substance?

Here, we have Clearly we can see that at the initial the mass of the radio-active substance is 100 gm . After 20 min the mass of the radio-active substance is 10 gm . So, half life of the radio-active substance is 100 2 gm = 50 gm If we draw a perpendicular from 50 gm to the curve it will intersect the curve at P , then draw another perpendicular from P to the x - axis. Where the perpendicular touches at x - axis, that will be the half life of the substance. Thus, we get Therefore, the half life of the substance is 6 . 5 min .

This graph shows how a radio-active substance loses its radioactivity over time. What mass of the substance is left after 20 minutes?

Here, we have Clearly we can see that at the initial the mass of the radio-active substance is 100 gm . If we draw a perpendicular from the end point of the curve to the y - axis, we get the mass left after 20 minutes. Thus, we get Therefore, after 20 min the mass of the radio-active substance is 10 gm .

In 2010 there were an estimated 1600 giant pandas in China Calculate the likely panda population in 2025 if there is an annual growth in the population of05

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 2

In $2010$ there were an estimated $1600$ giant pandas in China. Calculate the likely panda population in $2025$ if there is an annual decline in the population of $0.5 %$ .

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 3

A population of microbes in a laboratory doubles every day. At the start of the period, the population is estimated to be $1000000$ microbes. Copy and complete this table to show the growth in the population.

Time (Days)	$0$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$
Total number of microbes (Millions)	$1$	$2$	$4$

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 3

A population of microbes in a laboratory doubles every day. At the start of the period, the population is estimated to be $1000000$ microbes. Draw a graph to show the growth in the population over $8$ days.

Time (Days)	$0$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$
Total number of microbes (Millions)	$1$	$2$	$4$

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 3

A population of microbes in a laboratory doubles every day. At the start of the period, the population is estimated to be $1000000$ microbes. Draw a graph to show the growth in the population over $8$ days. Then use the graph to determine the microbe population after $2.5$ days.

Time (Days)	$0$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$
Total number of microbes (Millions)	$1$	$2$	$4$

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 3

A population of microbes in a laboratory doubles every day. At the start of the period, the population is estimated to be $1000000$ microbes. Draw a graph to show the growth in the population over $8$ days. Then use the graph to determine the microbe population after $3.6$ days.

Time (Days)	$0$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$
Total number of microbes (Millions)	$1$	$2$	$4$

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 3

A population of microbes in a laboratory doubles every day. At the start of the period, the population is estimated to be $1000000$ microbes. Draw a graph to show the growth in the population over $8$ days. Then use the graph to determine how long it will take the microbe population to reach $20$ million.

Time (Days)	$0$	$1$	$2$	$3$	$4$	$5$	$6$	$7$	$8$
Total number of microbes (Millions)	$1$	$2$	$4$

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 4

This graph shows how a radio-active substance loses its radioactivity over time.

Question Image

The half life of the substance is how long it takes to decay to half of its original mass. What is the half life of this substance?

EASY

Upper Secondary: IGCSE

IMPORTANT

Cambridge IGCSE® Mathematics Core and Extended Coursebook Second Edition>Chapter 17 - Managing Money>Exercise 17.7>Q 4

This graph shows how a radio-active substance loses its radioactivity over time.

Question Image

What mass of the substance is left after $20$ minutes?

In $2010$ there were an estimated $1600$ giant pandas in China. Calculate the likely panda population in $2025$ if there is an annual growth in the population of $0.5 %$ .

Important Questions on Managing Money

Learn and Prepare for any exam you want !

In 2010 there were an estimated 1600 giant pandas in China. Calculate the likely panda population in 2025 if there is an annual growth in the population of 0.5%.

Important Questions on Managing Money

Learn and Prepare for any exam you want !

In $2010$ there were an estimated $1600$ giant pandas in China. Calculate the likely panda population in $2025$ if there is an annual growth in the population of $0.5 %$ .