2024年4月3日发(作者：)

A tank with full water has a inverted circular cone with base of radius 5 m and

H of 10 m . If the tank has a hole and is leaking and the water level is decreasing at

the rate of 3 m/min –estimate the rate at which the tank is losing water when the

water level is only 5 m deep.

水槽装水的体积v=pi*52 *10/3=83.333pi

漏到5m深时水槽水的体积= pi*2.52 *5/3=10.416pi

漏掉水的体积=83.333pi-10.416pi=72.917pi=229.076m3

用掉的时间=229.076/3=76.36min

1、

An ant covers a distance of 90 metres in 3 hours. The average speed of the ant in

decimetres per minute is____.

2、

The Ancient Romans used the folling different numerals in their number system

I=1 V=5 X=10 L=50 C=100 D=500 M=1000 etc

they used these numerals to make up number as follows

I=1 II=2 III=3 IV=4 V=5 VI=6 VII=7 VIII=8

IX=9 X=10 etc

SO, for example, XCIX=99

What is the value of XLVI?

3、In a certain town some people were affected by a ’

flu’ epidemic. In the first month 20% of the population contracted the flu whilst

80% were healthy.

In the following month 20% of the sick people recovered and 20% of the heal

thy people contracted the disease.

What fraction of the population is healthy at the end of the second month?

4、Mpho, Barry, Sipho, Erica and Fatima are sitting on a park bench.

Mpho is not sitting on the far right. Barry is not sitting on the far left.

Sipho is not sitting at either end. Erica is sitting to the right of Barry,

but not necessarily next to him. Fatima is not sitting next to Sipho.

Sipho is not sitting next to Barry.

Who is sitting at the far right?