Question

to identical jars are filled with equal amount of marbles. the marbles are coloured red or white. the ratio of red to white marblesis 7:1 in jar 1 and 9:1 in jar 2 if there are 90 marbles altogether, determin the number of red marbles in jar 2.

Answer 1

let the number of white marbles in the first jar be x
then the number of red marbles in the first jar is 7x
total in jar 1 is 8x

let the number of white marbles in jar 2 be y
then the number of red marbles in jar 2 is 9y
total in jar 2 is 10y

but 8x = 10y
x = (5/4)y

also 8x + 10y = 90
8(5/4)y + 10y = 90
10y + 10y = 90
y = 4.5

but both x and y must be whole numbers,
Your question is flawed.

Answer 2

sorry the total of white marbles is 90