Question
Two alloys A and B are made of copper and zinc only. In
alloy A, copper and zinc are in the ratio 3 : 5. In alloy B, they are in the ratio 7 : 5. How many kilograms of alloy B must be mixed with 16 kg of alloy A so that the resulting alloy has 55% copper by weight?Solution
ATQ, In alloy A, copper fraction = 3/(3+5) = 3/8. In 16 kg of A, copper = 16 × 3/8 = 6 kg. Let x kg of alloy B be added. In alloy B, copper fraction = 7/(7+5) = 7/12. Copper in x kg of B = x × 7/12. Total copper = 6 + (7x/12). Total mass = 16 + x. Required copper % = 55% ⇒ (6 + 7x/12) / (16 + x) = 0.55 Multiply both sides by 12: (72 + 7x) / (16 + x) = 6.6 72 + 7x = 6.6(16 + x) 72 + 7x = 105.6 + 6.6x 7x − 6.6x = 105.6 − 72 0.4x = 33.6 ⇒ x = 84 kg.
Study the following series carefully and answer the questions based on it.
9 N 5 P 7 Q 7 E 8 G 9 W I 6 A 2 X 4 V 3 O 7 I 8 C
How many vo...
Select the combination of letters that when sequentially placed in the blanks of the given letter series will complete the series.
p _ q q q _...
If we remove all the letters from this series, then which of the following element will be 7th from left end?
__________ is a function inside another function.
1 Nibble is equal to
Which of the following is a non-volatile memory?
Select the combination of letter when placed sequentially in the blanks of the given series will complete the series.
u _ _ w _ y _ v _ _ _ y _ v...
How many such pairs of letters are there in the word ‘ ATTIRE ’ each of which has as many letters between them in the word in both directions as the...
Holding the mouse button down while moving an object or text is known as __
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at varianc...
