4. The exchange rate between US dollars and Singapore dollars is as shown in the table below.
1.42
1.37
1 US dollar
[2]
(a)
How much US dollars would Johnson get if he changed S$2500?
(b)
Johnson spent 75% of the US dollars that he changed. How much US dollars did he have
left?
[1]
(C)
How much Singapore dollars would he get if he changed his remaining US dollars back to
Singapore dollars?
[2]
[1]

x=30

step-by-step explanation:

b. 6

step-by-step explanation:

we are given the table representing an exponential function.

we can see from the table that, as x is increasing, the value of y is increasing in the power of 6.

i.e. the following relation is obtained,

x = 1, y = 6

x = 2, y = 36 =

x = 3, y = 216 =

x = 4, y = 1296 =

x = 5, y = 7776 =

so, the geometric series obtained is .

thus, the common ratio is given by = = 6.

hence, the common ratio is 6.