Question

X and Y are two alloys of Gold and Platinum prepared by mixing the metals in the ratio of 5:2 and 5:7, respectively. If we melt equal quantities of the alloys to form a third alloy Z, then the ratio of the quantity of Gold to the quantity of Platinum in Z will be:

• A. 84:73
• B. 95:73
• C. 95:84
• D. 73:95

Answer 1

Answer:

B. 95:73

$X=5:2$

$Y=5:7$

taking equal qty

$5+2=7$

$5+7=12$

LCM of 12 & 7 is 84

$X=5x+2x=84$ so $84/x=12$

new proportion of $X=60:24$

$Y=5x+7x=84$ so $84/12=7$

new proportion of $Y=35:49$

$Z=X+Y$

$Z=60+35:24+49$

$Z=95:73$