30b + 100u = 900
5b + 25u = 200....multiply by -6
------------------
30b + 100u = 900
-30b - 150u = - 1200 (result of multiplying by -6)
------------------add
-50u = - 300
u = 6 <== upgrated phones sold
30b + 100u = 900
30b + 100(6) = 900
30b + 600 = 900
30b = 900 - 600
30b = 300
b = 10 <== basic phones sold
Answer:
D
Step-by-step explanation:
11 per 1,000
Charlie spent $89 more dollars on ice cream than on yogurt. He spent a total of $96 on ice cream and $7 on yogurt. If you subtract 7 from 96 you get 89.
$96- $7= $89
The answer is c. Because all you need to know is to find the other leg and find the perimeter of the whole thing.
Answer:
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Question
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A boy is cycling such that the wheels of the cycle are making 140 revolutions per minute. If the diameter of the wheel is 60cm, calculate the speed per hour with which the boy is cycling.
Easy
Solution
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Radius of the wheel =r=
2
60
=30 cm
Circumference of the wheel =2πr=2×
7
22
×30=
7
1320
cm
Distance covered in 1 revolution =
7
1320
cm
Distance covered in 140 revolutions =
7
1320
×140=26400 cm=264 m=
1000
264
km
Distance covered in one minute = Distance covered in 140 revolutions =
1000
264
km
Distance covered in 1 hour =
1000
264
×60=15.84 km
Hence, the speed with which the boy is cycling is 15.84km/hr.
